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Coordination compounds of hydrazine derivatives with transition metals—VI
J. inorg, nucl. Chem., 1974, Vol. 36, pp. 551-556. Pergamon Press. Printed in Great Britain.
COORDINATION COMPOUNDS OF HYDRAZINE DERIVATIVES WITH TRANSITION M E T A L S - - V I THE REACTION OF AROYLHYDRAZINES WITH NICKEL(II), COBALT(II) AND COPPER(II) SALTS* M. F. ISKANDER, S. E. ZAYAN, M. A. KHALIFA and L. EL-SAYED Chemistry Department, Faculty of Science, Alexandria University, Egypt
(Received 21 January 1973)
Abstract--The reaction of aroylhydrazines with nickel(II), cobalt(II) and copper(II) ions were investigated. Both bis and tris nickel(II) and cobalt(II) chelates were isolated; magnetic and spectral measurements revealed their octahedral structure. With copper(II) nitrate and sulphate, aroylhydrazines gave only bis complexes. However, with copper(II) chloride, both mono and bis chelates were obtained at low temperature while at high temperature, oxidation-reduction reactions occurred with the formation of complexes with mixed oxidation states Ofcopper. In all the metal chelates prepared in this work, the aroylhydrazine molecule acted as a neutral bidentate ligand, coordinating via the carbonyl oxygen and the amino-nitrogen.
INTRODUCTION A~oYmn,m~,zmm and many other hydrazine derivatives have been reported to inhibit many reactions catalyzed by pyridoxal 5-phosphate as coenzyme[1]. The amino-oxidase enzyme requires such a coenzyme besides copper(II) ions for catalytic activity. The inhibition of monoamine oxidase will cause a rise in the level of catecholamines and sertonine in certain regions of the central nervous system. Many substituted acid hydrazides have been used for the treatment of psychotic and psychoneurotic conditions in which depression is the chief symptom[2]. The mode of action of the acid hydrazides is not certain, but it may be due to, (i) the reaction of acid hydrazides with the transition metal ion site in the amino oxidase enzyme, (ii) the reaction of acid hydrazide with the pyridoxal site to form the corresponding hydrazones[3], or (iii) the reaction of acid hydrazides with both transition metal ion and pyridoxal forming stable Sehiff base complexes, analogous to the reported pyridoxal amino acid chelates[4]. The antitubereular activity of acid hydrazides was also attributed to their ability to form chelates with copper(II) ions[5]. At this point, it seems necessary to investigate the * Abstracted from the M.Sc. Thesis of M. A. Khalifa.
reaction of acid hydrazides with divalent metal ions especially Cu(II) to gain information concerning the coordination chemistry of these molecules. Furthermore, the reactions of acid hydrazides with pyridoXal or similar molecules in the presence of transition metal ions are also required. In fact, the coordination chemistry of acid hydrazides has interested many authors[5-11]. This type of ligand was found to behave in different ways towards transition metal ions. They may function either as neutral or monobasic bidentate ligands, forming cationic and neutral complexes respectively[6-8]. The cationic complexes may be deprotonated by bases to give the corresponding neutral species. In tris cationic cobalt(II) and nickel(II) complexes, benzoylhydrazine was shown to act as neutral monodentate ligand coordinated in the imidol structure through the N 1.nitrogen [9]. However, with titanium, tin and antimony, acetyl and cyanoacetyl hydrazines react as monodentate ligands but with the carbonyl oxygen as the coordination site[10]. Recently, aroylhydrazines were reported to act as tribasic mono- and bidentate ligands, in some rhenium(V) complexes [ 11]. In this work, a series of metal chelates of some aroylhydrazines namely, benzoyl; ortho-hydroxy, paramethoxy- and para-nitrobenzoylhydrazines with cobalt(II), nickel(II) and copper(II) salts were isolated and identified. 551
M. F. ISKAND~,S. E. ZAYAN,M. A. KHALIFAand L. EL-SAYED
552
RESULTS AND DISCUSSION
Nickel(ll) and cobalt(II) complexes Aroylhydrazines (I, R = C6H5, p-CHaO.CeH4, o-HO. C6H4, p-NO2. C~H4) reacted with nickel(II) salts giving only the tris complexes (I-V) (Table 1). 1NH2-2NH-C-R
(1)
O With cobalt(II) salts, tris Co(II) complexes (VI-X) were also formed with benzoylhydrazine and the p-methoxy derivative while with o-hydroxy and pnitrobenzoylhydrazines, only bis cobalt(II) chloride complexes(XV, XVI) were isolated. Both nickel(II) and cobalt(II) thiocyanates gave exclusively bis complexes
(XI-XIV) and (XVII-XX), whatever the molar ratio of the metal ion "to ligand used in the reaction. The magnetic and electronic spectral data of the bis and tris complexes of both nickel(II) and cobalt(II) with aroylhydrazines are reported in Table 2. The values of the effective magnetic moments /Aff of Ni(II) (3.1-3.3 BM) and Co(II) (4.5- 4.9 BM) complexes suggest octahedral arrangement around the metal ion. The electronic spectra of these complexes confirm this assignment. The broadening or splitting of vt band at about 10,000 c m - 1 in the spectra of the Ni(II) complexes indicates some possibly tetragonal distortion. The electronic spectra of the bis and tris Co(II) complexes, in general, are also consistent with distorted octahedral structures[12]. However grinding samples of some bis thiocyanato complexes (XVII, XIX and XX) for mull spectral measurements causes a change of
Table 1. Analytical data of nickel(II), cobalt(II) and copper(II) complexes No.
Compound
Metal ~ Calcd. Found
Nitrogen(K) Calcd. Found
Halogen(K) Calcd. Found
I II III IV V
Ni(BzH)aCI2 Ni(BzH)aI2 Ni(BzH)aSO 4 . 2H20 Ni(p-CHaO. BzH)aC12 Ni(p-NO2BzH)aC12
10.9 8.14 9.80 9.34 8.72
10.6 8.43 9.50 9.19 8-7
15.61 11-65 14.02 13.37 18.7
15.45 11.31 14.10 13.27 ~ 18.25
13.17
13.17
11.29 10.53
11.30 10.60
VI VII VIII IX X
Co(BzH)3C12 Co(BzH)312 Co(BzH)a(NO3)2 Co(BzH)3SO4 Co(p-CH30. BzH)aC12
10.90 8.17 9.96 10.45 9.34
10.5 7.85 9.77 10.32 8.93
15.61 11.65 18.94 14:9i 13.37
15.70 11.35 18.57 14.58 13.23
13.17
13.20
11.29
11.30
XI XII XIV
Ni(BzH)2(SCN)2 Ni(o-HO. BzH)2(SCN)2 Ni(p-CH30. BzH)2(SCN)2 Ni(p-NO2. BzH)2(SCN)2
13.12 12,25 11.57 10.92
13.36 12.50 12.01 10.7
18.79 17.53 16.56 20.86
18.64 17.60 16.52 20.26
XV XVI XVII XVIII XIX XX
Co(o-HO. BzH)2C12 Co(p-NO2. BzH)2C12 Co(BzH)2(SCN)2 Co(o-HO. BzH)2(SCN)2 Co(p-CHaO. BzH)2(SCN)2 Co(p-NO 2 . BzH)2(SCN)2
13.57 11.97 13.14 12.29 11.61 10.96
13.34 12.02 13.02 12.15 11.70 11.10
12.90 17.07 18.78 17-53 16-56 20.85
12.80 17.00 18-35 17.05 16.20 20.73
16.33 14.40
16.34 14.52
XXI XXII XXIII XXIV XXV XXVI XXVII XXVIII XXIX XXX
Cu(BzH)2(NOa)2 Cu(o-HO. BzH)2('NOa)2 Cu(p-CHaO. BzH)2(NOa)2 Cu(p-NO2BzH)2(NOa)2 Cu(BzH)2SO4• 2H20 Cu(P-NO2BzH)2SO4 Cu(p-CHaO. BzH)2SO4 Cu(BzH)2C12 Cu(p-CHaO. BzH)2C1z Cu(o-HO. BzH)2C12
13.81 12.91 12.22 11.55 13.57 12.17 12.91 15.62 13.61 14.48
13.75 12.52 12.3 11.67 13.37 12.20 12.81 15.80 13.80 14.50
18.27 17-08 16.16 20.37 11.97 16.10 11.39 13.77 21.01 12.76
18.30 17.10 16.20 20.40 11.98 16.30 il.01 13.25 12.01 12.81
17.43 16.16 16.16
17.30 16.20 16.20
XXXI XXXII XXXIII XXXIV XXXV
Cu(BzH)C12 Cu(p-CHaO. BzH)C1z Cu2(BzH)2CIa Cuz(p-CHaO. BzH)2C1a Cu2(p-NO2. BzH)2Cla
23.83 21.13 25.12 22.46 21.33
24.00 21.20 25.12 22.50 21.42
10.50 9.31 11.07 9.90 14.10
10.30 9.22 11.20 9.96 14.20
26.59 23.58 21.02 18.80 17.85
26.80 23.50 18.30 18.30 17.35
XXXVI
Cu4(BzH)2CI5
36.11
36.30
7.96
7.71
25.18
25.20
XIII
BzH, p-NO2.. BzH, p-CH30. BzH and o-HO. BzH refer to benzoyl, p-nitro-, p-methoxy- and o-hydroxybenzoylhydrazines respectively.
Aroylhydrazine reactions with Ni(II), Co(II) and Cu(II) colour from rose pink to faint blue. The spectra of such complexes show new intense bands in the 15,00016,000 cm- 1 region besides those characteristic of an octahedral environment. The position and intensity of the additional band suggest the presence of tetrahedral Co(II). Solution spectra of the bis aroylhydrazine cobalt(II) complexes, in ethanol, show octahedral ~ tetrahedral equilibria, which are temperature dependent. The formation of the tetrahedral species is favoured by increasing the solution temperature.
Copper complexes The reaction of aroylhydrazine (I, R = C6H5, p-CH30. C6H4, p-NO 2 . CrH 4 and o-HO. C6H4) with copper(II) nitrate or sulphate in ethanol gave exclusively the cationic bis aroylhydrazine complexes even when (1 : 1) molar ratio of the reactants was used. With copper(II) chloride, however, the reaction seemed to be of a complex nature and different products were obtained, depending on the reaction temperature as well as the molar ratio of the reactants. In ice cold ethanolic solutions, benzoyl-, salicyloyland anisoylhydrazines reacted with copper(II) chloride in a (2:1) molar ratio yielding the bis complexes of the general formula [Cu(HL)2 C12] in which HL refers to the neutral aroylhydrazine molecule. On using (1:1) molar ratio of the reactants, benzoyl- and anisoylhydrazines gave the mono-complexes [Cu(HL)C12]. However, in boiling ethanol, the reaction of aroylhydrazines (I, R = CrHs, p-CH30.CsHa and pNOz.C6H¢) with copper(II) chloride in a (2:1) molar ratio gave crystalline products completely different from those obtained from the reaction in ice cold solutions. Elemental analyses (Table 1) are in accordance with the general formula [Cu2(HL)2 CI~]. Under the same conditions, but using (1:1) molar ration, benzoylhydrazine afforded a green complex [Cu4(BzH)2 Cls]. Generally, the reaction in boiling ethanol of the (1 : 1) or (1 : 2) molar ratio proceeded with the evolution of nitrogen and elimination of the aroylchloride. In this case of benzoylhydrazine, dibenzoylhydrazine was also isolated in high yield besides the complexes. The room temperature magnetic moments and the position of d-d absorption bands of all these complexes are listed in Table 3. The values of ~tefe of both mono and bis complexes lie within the normal range generally observed for copper(II) complexes[13]. The Nujol mull electronic spectra of the bis-complexes are similar to those reported for bis(semicarbazide) copper(II) chloride[14]. X-ray structural analyses of the latter complex [15] showed that the copper atom is in an octahedral environment, with the two semicarbazide molecules arranged trans to each other in the equatorial plane and the two chloride ions in trans axial position. A similar structure is likely for the bis(aroylhydrazine) copper(II) complexes. The spectra of the mono (aroylhydrazine) copper(II) shoulder at
553
12,500 cm-1 suggesting a more asymmetric environme/at. The paramagnetism of the complexes of the type [Cu2(HL)2C13] and [Cu4(HL)2Cls] (Table 3) indicates that there is only one cupric ion per molecule. These complexes must, accordingly be mixed valence complexes formulated as [CuII(HL)2CI2. CuIC1] and [Cu n(BzH)2C12 . 3CulC1] respectively. The higher #elf value of the complex (XXXVI) cannot be attributed to a large orbital contribution, but probably to partial oxidation of the cuprous ions in the molecule. The isolation of copper complexes containing both cupric and cuprous ions from the reaction of cupric chloride with aroylhydrazines, implies that oxidationreduction reactions are involved during complex formation. The mechanism of such reaction is not well established, but it appeared from the stoichiometry of the complexes isolated that aroylhydrazines partially reduce copper(II) to cuprous ions. These in turn, combined with the bis complex [Cu(HL)2C12] already formed in solution to give either [Cu(HL)2CI2. CuC1] or [Cu(HL)2C12.3CuC1] depending on the molar ratio of the reactants. The oxidation of hydrazine and substituted hydrazines with transition metals, giving dinitrogen or ammonia[15] is well known[16, 17]. Studies of chemical[16-19] as well as electrochemical[20] oxidations suggested that the first oxidation step is the formation of azoderivative which readily decomposes with evolution of nitrogen. However the azo intermediate can be stabilized through complex formation. In fact, from the reaction of methyl- and phenylhydrazine with copper(II), cuprous diazine compounds .were isolated[21, 22]. In a similar manner, the oxidation of aroylhydrazine with cupric ion may proceed through the formation ofR. CO. N----NH or R. CO. N = N - C 1 in presence of chloride ions. The latter compound was proposed by Carpino[23] as an intermediate in the oxidation of acid hydrazides with chlorine. The azo derivative is decomposed yielding nitrogen and the aroyl free radical. This can either combine with chloride ions, present in solution, to give aroylchloride or react with aroylhydrazine forming the diaroylhydrazine, Both benzoylchloride and dibenzoylhydrazine were identified in the reaction mixture of cupric chloride with benzoylhydrazine. Dibenzoylhydrazine was also reported as one of the oxidation products of benzoylhydrazine with iodine [24], mercuric oxide[24] or lead tetraacetate[25]. Data from the mull electronic spectra of the mixed cupric-cuprous complexes are given in Table 3. The spectra exhibit only the characteristic bands due to d-d transitions within the cupric ion. No intense bands are located in the visible region that might be attributed to interaction between cupric and cuprous ions within the molecule. This type of complex can be considered as class I in Robin and Day's classification[26], where the cupric and cuprous ions exist in different environments. The X-ray structural analysis of the complex [Cu(BzH)2C12 . 3CuC1] was reported by Baker,
M . F . ISKANDER,S. E. ZAYAN, M. A. KHALWAand L. EL-SAYED
554
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O O o OO
o
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a
II ¢'-lt~le,,l~l~l,.-~¢'-,It'q
3
Z
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,., . ~ I z l N ~ ' ~ I m N
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Aroylhydrazine reactions with Ni(II), Co01) and Cu(II)
555
Table 3. Magnetic moments and electronic spectra of copper(II) aroylhydrazine complexes in Nujol mull Compound
#af(T°K)
Cu(BzH)2(NOa)2 Cu(o-HOBzH)2 (NO3)2 Cu(p-CH30. BzH)2(NO3)2 Cu(BzH)2SO4.2H20 Cu(BzH)2CI2 Cu(p-CH30. BzH)2C12 Cu(o-HO. BzH)2C12 Cu(BzH)Cl 2 Cu2(BzH)2CIa Cu2(p-CH30 • BzHhC13
1.81(290) 1.81(290) 1-82(290) 1.82(293) 1.83(293) 1.83(293) 1.82(292) 1.84(294) 1.92(295) 21,740(sh) 1.89(294) 21,730(sh) 1.90(295) 2.30(293) 22,720(sh)
Cu2(p-NO 2 . BzH)2Cl 3
Cu4(BzH)2Cl5
Band maxima in cm15,400" 15,400* 15,450* 15,500" 16,950(sh) 15,400 12,990(sh) 16,950(sh) 1~500" 12,900(sh) 15,630(sh) 13,800" 12,500(sh) 15,750 13,160(sh) 16,950 15,300(sh) 15,150 14,100(sh) 15,620 14,000(sh)
*Broad band. Nyburg and Szymanski[27]. The N-benzoylhydrazine molecule acts in this molecule as a neutral bidentate ligand; the two benzoyl-hydrazine molecules are arranged in cis- configuration in the equatorial plane around the Cu(II) ion, with chloride ions in the axial positions of a distorted octahedron. All the five chloride ions in the molecule are bonded to the three Cu(I) ions in an infinite cylinder of distorted tetrahedra. The electronic spectra of this complex in nujol mull shows a broad band centered at 15,620 cm -1 with a well defined shoulder at 14,000 cm-1. The spectra of complexes of the type [Cu(HL)2C12 . CuCI], on the other hand, possess also a band located in the region 16,600-14,700 cm -1 with a shoulder at the lower energy side. The position of the band is largely affected by the nature of R in aroylhydrazine molecule. The ligand strength follows the order N-anisoyl (I, R = p-CH30. C6H4), N-benzoyl (I, R = C6H5), p-nitrobenzoylhydrazine (I, R = p-NO2 • C6H4) which is that expected from the electronic properties of the substituents.
Infrared spectra and mode of chelation It has been reported that benzoylhydrazine (I, R = C6H5) can function as a monodentate neutral ligand coordinated via the NZ-nitrogen in tris cobalt(II) and nickel(II) complexes. No corresponding bis c o m plexes were isolated and accordingly a penta-coordinate structure was assigned to the tris complexes[9]. However, many bis nickel(II) and cobalt(II) complexes with aroylhydrazines were prepared and identified in this work. Their magnetic and electronic spectral data are in agreement with octahedral environment around the central metal ion, thus implying that the aroylhydrazine functions as a neutral bidentate ligand. Apart from the i.r. bands characteristic of the anions, both tris and bis complexes of nickel(II), cobalt(II) and copper(II) exhibit the same i.r. spectra indicating the bidentate nature of the ligands. The amide I band v(C=O) of the parent aroylhydrazines located at 1660 c m - 1[28] is shifted to lower frequencies (1630 + 5) in all complexes. This band was assigned to the NH 2 _
bonding in the metal complexes with the ligand having the imidol structure I9]. Such assignment cannot be accepted since complexes of Schiff bases derived from aroylhydrazines with no amino group, show a similar band at the same position[29]. The shift to lower frequencies of the arnide I band upon complex formation may be attributed to coordination via the carbonyl oxygen as one of the coordination site. Similar behaviour was reported for metal(II)-semicarbazide [30], semicarbazones[30] and some substituted benzylidene aroylhydrazines[29]. The X-ray structural analyses[15] of Zn(II) and Cu(II) complexes with the analogous molecule semicarbazide (I, R = NH2) showed that the ligand is linked through the carbonyl oxygen and the amino group. Similarly, it is suggested that in aroylhydrazines, the amino group forms the second coordination site. With regard to the N H - stretching bands their position is not much affected upon coordination. This might be due to the presence of hydrogen bonding in the parent aroylhydrazines, similar to amides, which is replaced by coordination of the amino group to the central metal ion in the complexes.
EXPERIMENTAL
Preparation of N-aroylhydrazines The aroylhydrazines were generally prepared by the reaction of hydrazine hydrate with the corresponding ester. The following aroylhydrazines were prepared according to the methods reported in the literature; C6H 5. CO. NH. NH2 [31] p-CH30. C6H4. CO. NH. NH2132] p-NO2. C6H4. CO. NH. NH2 [33], o-HO. C6H 4 . CO. NH. NH2 [34].
Preparation of metal-complexes (i) Tris(N-aroylhydrazine) nickel(lI) and cobalt(ll) complexes. A solution of nickel(II) salts (0.01 mole) in ethanol (25 ~rrfl) was treated with a solution of aroylhydrazine (0.03 mole) in ethanol (30 ml). The reaction mixture was refluxed for ½hr. On cooling, the precipitated tris-nickel(II) complex was filtered, washed with hot ethanol then dried in a vacuum desiccator.
556
M.F. ISKANDER,S. E. ZAYAN,M. A. KaALIFA and L. EL-SAYED
The corresponding tris(aroylhydrazine) cobalt(II) comD. H. Abdulian, J. Pharmac. exp, Ther. 116, 62 (1956); plexes were prepared using the same procedure. R. G. Wiegand, J. Am. chem. Soc. 78, 5307 (1956). (ii) Bis(N-aroylhydrazine) nickel(II) and cobalt(lI) dithio4. D. E. Metzler, M. Ikawa and E. E. Snell, J. Am. chem. cyanate complexes. Nickel(II) nitrate hexahydrate (0.01 mole) Soc. 76, 648 (1954); E. E. Snell, Vitam. Horm. 16, 77 was dissolved in the minimum amount of absolute ethanol; (1958); B. M. Guirard and E. E. Snell, Comprehensive sodium thiocyanate was added in the mole ratio 1 : 2. The Biochemistry (Edited by M. Florkin and E: H. Stotz), sodium nitrate formed was filtered off. The nickel(II) Vol. 15, Chapter 5. Elsevier, New York (1964). solution was then treated with a solution of aroylhydrazine 5. J. Cymerman-Craig, D. Willis, S. D. Rubbo and (0.02 mole) in ethanol (40 ml), and the reaction mixture was J. Edgar, Nature, Lond. 176, 34 (1955). heated on a water bath for 10 min. The thiocyanato com6. S. Sorokin, W. Roth and H. Erlenmayer, Helv. Chim. plex precipitated on cooling, was filtered, washed with Acta 35, 1736 (1952); A. Albert, Experientia 9, 370 ethanol then dried in a vacuum desiccator. (1953); U. Tewari and S. D. Verma, J. Indian chem. Soc. The same procedure was adopted for the preparation of 29, 481 (1952). bis(N-aroylhydrazine) cobalt(II) dithiocyanate complexes. 7. K. Nagano, H. Kinoshita and A. Hirokawa, Chem. (iii) Bis(N-aroylhydrazine) copper(11) sulphate or nitrate. pharm. Bull. Tokyo 12, 1198 (1964). A hot solution of copper sulphate or nitrate (0-01 mole) in 8. R. M. Issa, M. F. E1-Shazly and M. F. Iskander, Z. water (20 ml) was added with constant stirring to a boiling anorg, allg. Chem. 235, 90 (1967). solution of aroylhydrazine (0.02 mole) in ethanol (40 ml). 9. A. Abroad and N. R. Chaudhuri, J. inorg, nucl. Chem. After complete addition, the reaction mixture was further 33, 189 (1971). stirred for 1 hr more. On cooling, the blue complex 10. R. C. Paul and S. L. Chadha, Spectrochim. Acts 23A, separated out, was filtered and washed with boiling ethanol 1249 (1967). then dried under vacuum. 11. J. Chatt, J. R. Dilworth, G. J. Leigh and V. D. Gupta, Mono(N-aroylhydrazine) copper(II) dichloride. This type J. chem. Soc. (A), 2631 (1971). of complexes was prepared using the same procedure used 12. R. L. Carlin, Transition Metal Chemistry (Edited by for his complexes, but using (1 : l) molar ratio of the reactants. L. Carlin), pp. 3-19. Edward Arnold, London (1965). Bis(N-aroylhydrazine) copper(ll) trichlorocuprate(l). A hot 13. B. J. Hathaway, J. chem. Soc. (A), 1196 (1972). solution of copper(II) dichloride dihydrate (0.01 mole) in 14. M. J. Campbell and R. Grzeskowiak, J. inorg, nucl. ethanol (20 ml) was treated with a solution of aroylhydrazine Chem. 30, 1865 (1968). (0.02 mole) in ethanol. The reaction mixture was refluxed 15. M. Nardelli, G. F. Gasparri, P. Bolddni and G. G. Battistini, Acts Crystallog. 19, 491 (1965). for 1 hr. On cooling, the complex formed was filtered, washed with absolute ethanol and dried in vacuum. 16. W. C. E. Higginson, Chem. Soc. Specialpubl., No. 10, In case of benzoylhydrazine, the mother liquor from the 95, 1957. above preparation was left over night; a white silky product 17. F. Bottomley, Q. rev. Chem. Soc. 24, 617 (1970). separated out. This product (m.p. 235"C) showed i.r. 18. J. B. Aylward, J. chem. $oc. (C), 1663 (1969). spectrum identical to that of dibenzoylhydrazine. 19. J. B. Aylward, Q. rev. Chem. Soc. 25, 418 (1971). Bis(N-benzoylhydrazine) copper(II) pentachlorotri- 20. H. Lund, Colin. Czech. Chem. Commun. 30, 4237 cuprate(1). This complex was prepared using the method (1965); idem. Tetrahedron Letters, 365 (1968). reported by Baker et al.[27]. 21. D. Petredis, A. Burke and A. L. Balch, J. Am. chem. Soc. 92, 428 (1970). 22. M. N. Ackermann, lnorg. Chem. 10, 272 (1971). Physical measurements 23. L. A. Carpino, J. Am. chem. Soc. 79, 96 (1957). Magnetic measurements, i,r. and electronic spectra were 24. T. Curtius, J. Prakt. Chem. 50, 275-294 (1894). obtained using the same procedures previously des- 25. J. B. Ayiward and R. O. C. Norman, J. chem. Soc. (C), 2399 (1968). cribed[29]. 26. M. B. Robin and P. Day, Advanc. inorg, chem. Radio. chem. 10, 248 (1967). REFERENCES 27. R. J. Baker, S. C. Nyburg and J. T. S. Szymanski, lnorg. Chem. 10, 138 (1971). 1. E. A. ZeUer, J. Barsky, J. R. Fouts, W. F. Kirchheimer 28. M. Mashima, Bull. chem. $oc. Japan 35, 1882 (1962); and L. S. Van Orden, Experimentia 8, 349 (1952); 36, 210 (1963). M. Yoneda, N. Kato and M. Okajima, Nature, Lond. 29. L. E1-Sayed and M. F. iskander, J. inorg, nucl. Chem. 170, 803 (1952); D. S. Hoare, Biochim. biophys. Acta 33, 435 (1971). 19, 141 (1956); A. N. Davisen, ibid. 19, 131 (1956); 30. H. EI-Khadem, M. F. Iskander and S. E. Zayan, Z. A. Kurosawa, Chem. pharm. Bull. Tokyo 17 (1), 49 anorg, allg. Chem. 320, 261 (1963). (1969). 31. G. Strnve, J.prakt. Chem. 50, 295 (1894). 2. J. H. Biel, A. Horita and A. E. Drukker, Psycho 32. R. Stolle and F. Stevens, J. prakt. Chem. 69, 369 (1904). Pharmacological Agents (Edited by M. Gordon), Vol. I. 33. T. Curtuis and O. Trachmann, J. prakt. Chem. 51, 165 Academic Press, New York (1964). (1895). 3. R. W. Vilter, J. P. Biehl, J. F. Mueller and B. J. Fried- 34. W. Baker, C. N. Haksar and J. F. W. McOmie, J. chem. man, Federation Proc. 13, 776 (1954); H. L. Williams, Soc. 170 (1950).
COORDINATION COMPOUNDS OF HYDRAZINE DERIVATIVES WITH TRANSITION M E T A L S - - V I THE REACTION OF AROYLHYDRAZINES WITH NICKEL(II), COBALT(II) AND COPPER(II) SALTS* M. F. ISKANDER, S. E. ZAYAN, M. A. KHALIFA and L. EL-SAYED Chemistry Department, Faculty of Science, Alexandria University, Egypt
(Received 21 January 1973)
Abstract--The reaction of aroylhydrazines with nickel(II), cobalt(II) and copper(II) ions were investigated. Both bis and tris nickel(II) and cobalt(II) chelates were isolated; magnetic and spectral measurements revealed their octahedral structure. With copper(II) nitrate and sulphate, aroylhydrazines gave only bis complexes. However, with copper(II) chloride, both mono and bis chelates were obtained at low temperature while at high temperature, oxidation-reduction reactions occurred with the formation of complexes with mixed oxidation states Ofcopper. In all the metal chelates prepared in this work, the aroylhydrazine molecule acted as a neutral bidentate ligand, coordinating via the carbonyl oxygen and the amino-nitrogen.
INTRODUCTION A~oYmn,m~,zmm and many other hydrazine derivatives have been reported to inhibit many reactions catalyzed by pyridoxal 5-phosphate as coenzyme[1]. The amino-oxidase enzyme requires such a coenzyme besides copper(II) ions for catalytic activity. The inhibition of monoamine oxidase will cause a rise in the level of catecholamines and sertonine in certain regions of the central nervous system. Many substituted acid hydrazides have been used for the treatment of psychotic and psychoneurotic conditions in which depression is the chief symptom[2]. The mode of action of the acid hydrazides is not certain, but it may be due to, (i) the reaction of acid hydrazides with the transition metal ion site in the amino oxidase enzyme, (ii) the reaction of acid hydrazide with the pyridoxal site to form the corresponding hydrazones[3], or (iii) the reaction of acid hydrazides with both transition metal ion and pyridoxal forming stable Sehiff base complexes, analogous to the reported pyridoxal amino acid chelates[4]. The antitubereular activity of acid hydrazides was also attributed to their ability to form chelates with copper(II) ions[5]. At this point, it seems necessary to investigate the * Abstracted from the M.Sc. Thesis of M. A. Khalifa.
reaction of acid hydrazides with divalent metal ions especially Cu(II) to gain information concerning the coordination chemistry of these molecules. Furthermore, the reactions of acid hydrazides with pyridoXal or similar molecules in the presence of transition metal ions are also required. In fact, the coordination chemistry of acid hydrazides has interested many authors[5-11]. This type of ligand was found to behave in different ways towards transition metal ions. They may function either as neutral or monobasic bidentate ligands, forming cationic and neutral complexes respectively[6-8]. The cationic complexes may be deprotonated by bases to give the corresponding neutral species. In tris cationic cobalt(II) and nickel(II) complexes, benzoylhydrazine was shown to act as neutral monodentate ligand coordinated in the imidol structure through the N 1.nitrogen [9]. However, with titanium, tin and antimony, acetyl and cyanoacetyl hydrazines react as monodentate ligands but with the carbonyl oxygen as the coordination site[10]. Recently, aroylhydrazines were reported to act as tribasic mono- and bidentate ligands, in some rhenium(V) complexes [ 11]. In this work, a series of metal chelates of some aroylhydrazines namely, benzoyl; ortho-hydroxy, paramethoxy- and para-nitrobenzoylhydrazines with cobalt(II), nickel(II) and copper(II) salts were isolated and identified. 551
M. F. ISKAND~,S. E. ZAYAN,M. A. KHALIFAand L. EL-SAYED
552
RESULTS AND DISCUSSION
Nickel(ll) and cobalt(II) complexes Aroylhydrazines (I, R = C6H5, p-CHaO.CeH4, o-HO. C6H4, p-NO2. C~H4) reacted with nickel(II) salts giving only the tris complexes (I-V) (Table 1). 1NH2-2NH-C-R
(1)
O With cobalt(II) salts, tris Co(II) complexes (VI-X) were also formed with benzoylhydrazine and the p-methoxy derivative while with o-hydroxy and pnitrobenzoylhydrazines, only bis cobalt(II) chloride complexes(XV, XVI) were isolated. Both nickel(II) and cobalt(II) thiocyanates gave exclusively bis complexes
(XI-XIV) and (XVII-XX), whatever the molar ratio of the metal ion "to ligand used in the reaction. The magnetic and electronic spectral data of the bis and tris complexes of both nickel(II) and cobalt(II) with aroylhydrazines are reported in Table 2. The values of the effective magnetic moments /Aff of Ni(II) (3.1-3.3 BM) and Co(II) (4.5- 4.9 BM) complexes suggest octahedral arrangement around the metal ion. The electronic spectra of these complexes confirm this assignment. The broadening or splitting of vt band at about 10,000 c m - 1 in the spectra of the Ni(II) complexes indicates some possibly tetragonal distortion. The electronic spectra of the bis and tris Co(II) complexes, in general, are also consistent with distorted octahedral structures[12]. However grinding samples of some bis thiocyanato complexes (XVII, XIX and XX) for mull spectral measurements causes a change of
Table 1. Analytical data of nickel(II), cobalt(II) and copper(II) complexes No.
Compound
Metal ~ Calcd. Found
Nitrogen(K) Calcd. Found
Halogen(K) Calcd. Found
I II III IV V
Ni(BzH)aCI2 Ni(BzH)aI2 Ni(BzH)aSO 4 . 2H20 Ni(p-CHaO. BzH)aC12 Ni(p-NO2BzH)aC12
10.9 8.14 9.80 9.34 8.72
10.6 8.43 9.50 9.19 8-7
15.61 11-65 14.02 13.37 18.7
15.45 11.31 14.10 13.27 ~ 18.25
13.17
13.17
11.29 10.53
11.30 10.60
VI VII VIII IX X
Co(BzH)3C12 Co(BzH)312 Co(BzH)a(NO3)2 Co(BzH)3SO4 Co(p-CH30. BzH)aC12
10.90 8.17 9.96 10.45 9.34
10.5 7.85 9.77 10.32 8.93
15.61 11.65 18.94 14:9i 13.37
15.70 11.35 18.57 14.58 13.23
13.17
13.20
11.29
11.30
XI XII XIV
Ni(BzH)2(SCN)2 Ni(o-HO. BzH)2(SCN)2 Ni(p-CH30. BzH)2(SCN)2 Ni(p-NO2. BzH)2(SCN)2
13.12 12,25 11.57 10.92
13.36 12.50 12.01 10.7
18.79 17.53 16.56 20.86
18.64 17.60 16.52 20.26
XV XVI XVII XVIII XIX XX
Co(o-HO. BzH)2C12 Co(p-NO2. BzH)2C12 Co(BzH)2(SCN)2 Co(o-HO. BzH)2(SCN)2 Co(p-CHaO. BzH)2(SCN)2 Co(p-NO 2 . BzH)2(SCN)2
13.57 11.97 13.14 12.29 11.61 10.96
13.34 12.02 13.02 12.15 11.70 11.10
12.90 17.07 18.78 17-53 16-56 20.85
12.80 17.00 18-35 17.05 16.20 20.73
16.33 14.40
16.34 14.52
XXI XXII XXIII XXIV XXV XXVI XXVII XXVIII XXIX XXX
Cu(BzH)2(NOa)2 Cu(o-HO. BzH)2('NOa)2 Cu(p-CHaO. BzH)2(NOa)2 Cu(p-NO2BzH)2(NOa)2 Cu(BzH)2SO4• 2H20 Cu(P-NO2BzH)2SO4 Cu(p-CHaO. BzH)2SO4 Cu(BzH)2C12 Cu(p-CHaO. BzH)2C1z Cu(o-HO. BzH)2C12
13.81 12.91 12.22 11.55 13.57 12.17 12.91 15.62 13.61 14.48
13.75 12.52 12.3 11.67 13.37 12.20 12.81 15.80 13.80 14.50
18.27 17-08 16.16 20.37 11.97 16.10 11.39 13.77 21.01 12.76
18.30 17.10 16.20 20.40 11.98 16.30 il.01 13.25 12.01 12.81
17.43 16.16 16.16
17.30 16.20 16.20
XXXI XXXII XXXIII XXXIV XXXV
Cu(BzH)C12 Cu(p-CHaO. BzH)C1z Cu2(BzH)2CIa Cuz(p-CHaO. BzH)2C1a Cu2(p-NO2. BzH)2Cla
23.83 21.13 25.12 22.46 21.33
24.00 21.20 25.12 22.50 21.42
10.50 9.31 11.07 9.90 14.10
10.30 9.22 11.20 9.96 14.20
26.59 23.58 21.02 18.80 17.85
26.80 23.50 18.30 18.30 17.35
XXXVI
Cu4(BzH)2CI5
36.11
36.30
7.96
7.71
25.18
25.20
XIII
BzH, p-NO2.. BzH, p-CH30. BzH and o-HO. BzH refer to benzoyl, p-nitro-, p-methoxy- and o-hydroxybenzoylhydrazines respectively.
Aroylhydrazine reactions with Ni(II), Co(II) and Cu(II) colour from rose pink to faint blue. The spectra of such complexes show new intense bands in the 15,00016,000 cm- 1 region besides those characteristic of an octahedral environment. The position and intensity of the additional band suggest the presence of tetrahedral Co(II). Solution spectra of the bis aroylhydrazine cobalt(II) complexes, in ethanol, show octahedral ~ tetrahedral equilibria, which are temperature dependent. The formation of the tetrahedral species is favoured by increasing the solution temperature.
Copper complexes The reaction of aroylhydrazine (I, R = C6H5, p-CH30. C6H4, p-NO 2 . CrH 4 and o-HO. C6H4) with copper(II) nitrate or sulphate in ethanol gave exclusively the cationic bis aroylhydrazine complexes even when (1 : 1) molar ratio of the reactants was used. With copper(II) chloride, however, the reaction seemed to be of a complex nature and different products were obtained, depending on the reaction temperature as well as the molar ratio of the reactants. In ice cold ethanolic solutions, benzoyl-, salicyloyland anisoylhydrazines reacted with copper(II) chloride in a (2:1) molar ratio yielding the bis complexes of the general formula [Cu(HL)2 C12] in which HL refers to the neutral aroylhydrazine molecule. On using (1:1) molar ratio of the reactants, benzoyl- and anisoylhydrazines gave the mono-complexes [Cu(HL)C12]. However, in boiling ethanol, the reaction of aroylhydrazines (I, R = CrHs, p-CH30.CsHa and pNOz.C6H¢) with copper(II) chloride in a (2:1) molar ratio gave crystalline products completely different from those obtained from the reaction in ice cold solutions. Elemental analyses (Table 1) are in accordance with the general formula [Cu2(HL)2 CI~]. Under the same conditions, but using (1:1) molar ration, benzoylhydrazine afforded a green complex [Cu4(BzH)2 Cls]. Generally, the reaction in boiling ethanol of the (1 : 1) or (1 : 2) molar ratio proceeded with the evolution of nitrogen and elimination of the aroylchloride. In this case of benzoylhydrazine, dibenzoylhydrazine was also isolated in high yield besides the complexes. The room temperature magnetic moments and the position of d-d absorption bands of all these complexes are listed in Table 3. The values of ~tefe of both mono and bis complexes lie within the normal range generally observed for copper(II) complexes[13]. The Nujol mull electronic spectra of the bis-complexes are similar to those reported for bis(semicarbazide) copper(II) chloride[14]. X-ray structural analyses of the latter complex [15] showed that the copper atom is in an octahedral environment, with the two semicarbazide molecules arranged trans to each other in the equatorial plane and the two chloride ions in trans axial position. A similar structure is likely for the bis(aroylhydrazine) copper(II) complexes. The spectra of the mono (aroylhydrazine) copper(II) shoulder at
553
12,500 cm-1 suggesting a more asymmetric environme/at. The paramagnetism of the complexes of the type [Cu2(HL)2C13] and [Cu4(HL)2Cls] (Table 3) indicates that there is only one cupric ion per molecule. These complexes must, accordingly be mixed valence complexes formulated as [CuII(HL)2CI2. CuIC1] and [Cu n(BzH)2C12 . 3CulC1] respectively. The higher #elf value of the complex (XXXVI) cannot be attributed to a large orbital contribution, but probably to partial oxidation of the cuprous ions in the molecule. The isolation of copper complexes containing both cupric and cuprous ions from the reaction of cupric chloride with aroylhydrazines, implies that oxidationreduction reactions are involved during complex formation. The mechanism of such reaction is not well established, but it appeared from the stoichiometry of the complexes isolated that aroylhydrazines partially reduce copper(II) to cuprous ions. These in turn, combined with the bis complex [Cu(HL)2C12] already formed in solution to give either [Cu(HL)2CI2. CuC1] or [Cu(HL)2C12.3CuC1] depending on the molar ratio of the reactants. The oxidation of hydrazine and substituted hydrazines with transition metals, giving dinitrogen or ammonia[15] is well known[16, 17]. Studies of chemical[16-19] as well as electrochemical[20] oxidations suggested that the first oxidation step is the formation of azoderivative which readily decomposes with evolution of nitrogen. However the azo intermediate can be stabilized through complex formation. In fact, from the reaction of methyl- and phenylhydrazine with copper(II), cuprous diazine compounds .were isolated[21, 22]. In a similar manner, the oxidation of aroylhydrazine with cupric ion may proceed through the formation ofR. CO. N----NH or R. CO. N = N - C 1 in presence of chloride ions. The latter compound was proposed by Carpino[23] as an intermediate in the oxidation of acid hydrazides with chlorine. The azo derivative is decomposed yielding nitrogen and the aroyl free radical. This can either combine with chloride ions, present in solution, to give aroylchloride or react with aroylhydrazine forming the diaroylhydrazine, Both benzoylchloride and dibenzoylhydrazine were identified in the reaction mixture of cupric chloride with benzoylhydrazine. Dibenzoylhydrazine was also reported as one of the oxidation products of benzoylhydrazine with iodine [24], mercuric oxide[24] or lead tetraacetate[25]. Data from the mull electronic spectra of the mixed cupric-cuprous complexes are given in Table 3. The spectra exhibit only the characteristic bands due to d-d transitions within the cupric ion. No intense bands are located in the visible region that might be attributed to interaction between cupric and cuprous ions within the molecule. This type of complex can be considered as class I in Robin and Day's classification[26], where the cupric and cuprous ions exist in different environments. The X-ray structural analysis of the complex [Cu(BzH)2C12 . 3CuC1] was reported by Baker,
M . F . ISKANDER,S. E. ZAYAN, M. A. KHALWAand L. EL-SAYED
554
N
O O o OO
o
flflfiflflZZZfl
a
II ¢'-lt~le,,l~l~l,.-~¢'-,It'q
3
Z
O
o
O
0
N
-b" P.~
N ~-
e~ e ~ . ~
,., . ~ I z l N ~ ' ~ I m N
~ 0 ~,~0 ~ 0 ~ 0 ~ 0
~,
D ~ O ~
"~O
•
~,~,~: o o ~o ~o N NU~Z 00
O
N~UZ
O O
O
.o H
Aroylhydrazine reactions with Ni(II), Co01) and Cu(II)
555
Table 3. Magnetic moments and electronic spectra of copper(II) aroylhydrazine complexes in Nujol mull Compound
#af(T°K)
Cu(BzH)2(NOa)2 Cu(o-HOBzH)2 (NO3)2 Cu(p-CH30. BzH)2(NO3)2 Cu(BzH)2SO4.2H20 Cu(BzH)2CI2 Cu(p-CH30. BzH)2C12 Cu(o-HO. BzH)2C12 Cu(BzH)Cl 2 Cu2(BzH)2CIa Cu2(p-CH30 • BzHhC13
1.81(290) 1.81(290) 1-82(290) 1.82(293) 1.83(293) 1.83(293) 1.82(292) 1.84(294) 1.92(295) 21,740(sh) 1.89(294) 21,730(sh) 1.90(295) 2.30(293) 22,720(sh)
Cu2(p-NO 2 . BzH)2Cl 3
Cu4(BzH)2Cl5
Band maxima in cm15,400" 15,400* 15,450* 15,500" 16,950(sh) 15,400 12,990(sh) 16,950(sh) 1~500" 12,900(sh) 15,630(sh) 13,800" 12,500(sh) 15,750 13,160(sh) 16,950 15,300(sh) 15,150 14,100(sh) 15,620 14,000(sh)
*Broad band. Nyburg and Szymanski[27]. The N-benzoylhydrazine molecule acts in this molecule as a neutral bidentate ligand; the two benzoyl-hydrazine molecules are arranged in cis- configuration in the equatorial plane around the Cu(II) ion, with chloride ions in the axial positions of a distorted octahedron. All the five chloride ions in the molecule are bonded to the three Cu(I) ions in an infinite cylinder of distorted tetrahedra. The electronic spectra of this complex in nujol mull shows a broad band centered at 15,620 cm -1 with a well defined shoulder at 14,000 cm-1. The spectra of complexes of the type [Cu(HL)2C12 . CuCI], on the other hand, possess also a band located in the region 16,600-14,700 cm -1 with a shoulder at the lower energy side. The position of the band is largely affected by the nature of R in aroylhydrazine molecule. The ligand strength follows the order N-anisoyl (I, R = p-CH30. C6H4), N-benzoyl (I, R = C6H5), p-nitrobenzoylhydrazine (I, R = p-NO2 • C6H4) which is that expected from the electronic properties of the substituents.
Infrared spectra and mode of chelation It has been reported that benzoylhydrazine (I, R = C6H5) can function as a monodentate neutral ligand coordinated via the NZ-nitrogen in tris cobalt(II) and nickel(II) complexes. No corresponding bis c o m plexes were isolated and accordingly a penta-coordinate structure was assigned to the tris complexes[9]. However, many bis nickel(II) and cobalt(II) complexes with aroylhydrazines were prepared and identified in this work. Their magnetic and electronic spectral data are in agreement with octahedral environment around the central metal ion, thus implying that the aroylhydrazine functions as a neutral bidentate ligand. Apart from the i.r. bands characteristic of the anions, both tris and bis complexes of nickel(II), cobalt(II) and copper(II) exhibit the same i.r. spectra indicating the bidentate nature of the ligands. The amide I band v(C=O) of the parent aroylhydrazines located at 1660 c m - 1[28] is shifted to lower frequencies (1630 + 5) in all complexes. This band was assigned to the NH 2 _
bonding in the metal complexes with the ligand having the imidol structure I9]. Such assignment cannot be accepted since complexes of Schiff bases derived from aroylhydrazines with no amino group, show a similar band at the same position[29]. The shift to lower frequencies of the arnide I band upon complex formation may be attributed to coordination via the carbonyl oxygen as one of the coordination site. Similar behaviour was reported for metal(II)-semicarbazide [30], semicarbazones[30] and some substituted benzylidene aroylhydrazines[29]. The X-ray structural analyses[15] of Zn(II) and Cu(II) complexes with the analogous molecule semicarbazide (I, R = NH2) showed that the ligand is linked through the carbonyl oxygen and the amino group. Similarly, it is suggested that in aroylhydrazines, the amino group forms the second coordination site. With regard to the N H - stretching bands their position is not much affected upon coordination. This might be due to the presence of hydrogen bonding in the parent aroylhydrazines, similar to amides, which is replaced by coordination of the amino group to the central metal ion in the complexes.
EXPERIMENTAL
Preparation of N-aroylhydrazines The aroylhydrazines were generally prepared by the reaction of hydrazine hydrate with the corresponding ester. The following aroylhydrazines were prepared according to the methods reported in the literature; C6H 5. CO. NH. NH2 [31] p-CH30. C6H4. CO. NH. NH2132] p-NO2. C6H4. CO. NH. NH2 [33], o-HO. C6H 4 . CO. NH. NH2 [34].
Preparation of metal-complexes (i) Tris(N-aroylhydrazine) nickel(lI) and cobalt(ll) complexes. A solution of nickel(II) salts (0.01 mole) in ethanol (25 ~rrfl) was treated with a solution of aroylhydrazine (0.03 mole) in ethanol (30 ml). The reaction mixture was refluxed for ½hr. On cooling, the precipitated tris-nickel(II) complex was filtered, washed with hot ethanol then dried in a vacuum desiccator.
556
M.F. ISKANDER,S. E. ZAYAN,M. A. KaALIFA and L. EL-SAYED
The corresponding tris(aroylhydrazine) cobalt(II) comD. H. Abdulian, J. Pharmac. exp, Ther. 116, 62 (1956); plexes were prepared using the same procedure. R. G. Wiegand, J. Am. chem. Soc. 78, 5307 (1956). (ii) Bis(N-aroylhydrazine) nickel(II) and cobalt(lI) dithio4. D. E. Metzler, M. Ikawa and E. E. Snell, J. Am. chem. cyanate complexes. Nickel(II) nitrate hexahydrate (0.01 mole) Soc. 76, 648 (1954); E. E. Snell, Vitam. Horm. 16, 77 was dissolved in the minimum amount of absolute ethanol; (1958); B. M. Guirard and E. E. Snell, Comprehensive sodium thiocyanate was added in the mole ratio 1 : 2. The Biochemistry (Edited by M. Florkin and E: H. Stotz), sodium nitrate formed was filtered off. The nickel(II) Vol. 15, Chapter 5. Elsevier, New York (1964). solution was then treated with a solution of aroylhydrazine 5. J. Cymerman-Craig, D. Willis, S. D. Rubbo and (0.02 mole) in ethanol (40 ml), and the reaction mixture was J. Edgar, Nature, Lond. 176, 34 (1955). heated on a water bath for 10 min. The thiocyanato com6. S. Sorokin, W. Roth and H. Erlenmayer, Helv. Chim. plex precipitated on cooling, was filtered, washed with Acta 35, 1736 (1952); A. Albert, Experientia 9, 370 ethanol then dried in a vacuum desiccator. (1953); U. Tewari and S. D. Verma, J. Indian chem. Soc. The same procedure was adopted for the preparation of 29, 481 (1952). bis(N-aroylhydrazine) cobalt(II) dithiocyanate complexes. 7. K. Nagano, H. Kinoshita and A. Hirokawa, Chem. (iii) Bis(N-aroylhydrazine) copper(11) sulphate or nitrate. pharm. Bull. Tokyo 12, 1198 (1964). A hot solution of copper sulphate or nitrate (0-01 mole) in 8. R. M. Issa, M. F. E1-Shazly and M. F. Iskander, Z. water (20 ml) was added with constant stirring to a boiling anorg, allg. Chem. 235, 90 (1967). solution of aroylhydrazine (0.02 mole) in ethanol (40 ml). 9. A. Abroad and N. R. Chaudhuri, J. inorg, nucl. Chem. After complete addition, the reaction mixture was further 33, 189 (1971). stirred for 1 hr more. On cooling, the blue complex 10. R. C. Paul and S. L. Chadha, Spectrochim. Acts 23A, separated out, was filtered and washed with boiling ethanol 1249 (1967). then dried under vacuum. 11. J. Chatt, J. R. Dilworth, G. J. Leigh and V. D. Gupta, Mono(N-aroylhydrazine) copper(II) dichloride. This type J. chem. Soc. (A), 2631 (1971). of complexes was prepared using the same procedure used 12. R. L. Carlin, Transition Metal Chemistry (Edited by for his complexes, but using (1 : l) molar ratio of the reactants. L. Carlin), pp. 3-19. Edward Arnold, London (1965). Bis(N-aroylhydrazine) copper(ll) trichlorocuprate(l). A hot 13. B. J. Hathaway, J. chem. Soc. (A), 1196 (1972). solution of copper(II) dichloride dihydrate (0.01 mole) in 14. M. J. Campbell and R. Grzeskowiak, J. inorg, nucl. ethanol (20 ml) was treated with a solution of aroylhydrazine Chem. 30, 1865 (1968). (0.02 mole) in ethanol. The reaction mixture was refluxed 15. M. Nardelli, G. F. Gasparri, P. Bolddni and G. G. Battistini, Acts Crystallog. 19, 491 (1965). for 1 hr. On cooling, the complex formed was filtered, washed with absolute ethanol and dried in vacuum. 16. W. C. E. Higginson, Chem. Soc. Specialpubl., No. 10, In case of benzoylhydrazine, the mother liquor from the 95, 1957. above preparation was left over night; a white silky product 17. F. Bottomley, Q. rev. Chem. Soc. 24, 617 (1970). separated out. This product (m.p. 235"C) showed i.r. 18. J. B. Aylward, J. chem. $oc. (C), 1663 (1969). spectrum identical to that of dibenzoylhydrazine. 19. J. B. Aylward, Q. rev. Chem. Soc. 25, 418 (1971). Bis(N-benzoylhydrazine) copper(II) pentachlorotri- 20. H. Lund, Colin. Czech. Chem. Commun. 30, 4237 cuprate(1). This complex was prepared using the method (1965); idem. Tetrahedron Letters, 365 (1968). reported by Baker et al.[27]. 21. D. Petredis, A. Burke and A. L. Balch, J. Am. chem. Soc. 92, 428 (1970). 22. M. N. Ackermann, lnorg. Chem. 10, 272 (1971). Physical measurements 23. L. A. Carpino, J. Am. chem. Soc. 79, 96 (1957). Magnetic measurements, i,r. and electronic spectra were 24. T. Curtius, J. Prakt. Chem. 50, 275-294 (1894). obtained using the same procedures previously des- 25. J. B. Ayiward and R. O. C. Norman, J. chem. Soc. (C), 2399 (1968). cribed[29]. 26. M. B. Robin and P. Day, Advanc. inorg, chem. Radio. chem. 10, 248 (1967). REFERENCES 27. R. J. Baker, S. C. Nyburg and J. T. S. Szymanski, lnorg. Chem. 10, 138 (1971). 1. E. A. ZeUer, J. Barsky, J. R. Fouts, W. F. Kirchheimer 28. M. Mashima, Bull. chem. $oc. Japan 35, 1882 (1962); and L. S. Van Orden, Experimentia 8, 349 (1952); 36, 210 (1963). M. Yoneda, N. Kato and M. Okajima, Nature, Lond. 29. L. E1-Sayed and M. F. iskander, J. inorg, nucl. Chem. 170, 803 (1952); D. S. Hoare, Biochim. biophys. Acta 33, 435 (1971). 19, 141 (1956); A. N. Davisen, ibid. 19, 131 (1956); 30. H. EI-Khadem, M. F. Iskander and S. E. Zayan, Z. A. Kurosawa, Chem. pharm. Bull. Tokyo 17 (1), 49 anorg, allg. Chem. 320, 261 (1963). (1969). 31. G. Strnve, J.prakt. Chem. 50, 295 (1894). 2. J. H. Biel, A. Horita and A. E. Drukker, Psycho 32. R. Stolle and F. Stevens, J. prakt. Chem. 69, 369 (1904). Pharmacological Agents (Edited by M. Gordon), Vol. I. 33. T. Curtuis and O. Trachmann, J. prakt. Chem. 51, 165 Academic Press, New York (1964). (1895). 3. R. W. Vilter, J. P. Biehl, J. F. Mueller and B. J. Fried- 34. W. Baker, C. N. Haksar and J. F. W. McOmie, J. chem. man, Federation Proc. 13, 776 (1954); H. L. Williams, Soc. 170 (1950).