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Antimony and bismuth trihalide complexes of dithiomalonamide, N,N′-dimethyl- and N,N′-diphenyl-dithiomalonamide
1855
Notes Table 2. Characteristicinfraredvibrations(cm -~) of the complexes of tn'chlortitanium(IV)alkoxides with some oxygendonor iigands Complex A. DMF A. DMA A. TMU A. TPPO A. HMPT A. 2Py-O A. 2(2Pic-O) A. 2(3PiC-O) A. 2(4Pic-O) B. DMF B. DMA B. TMU B. TPPO B. HMPT B. 2Py-O B. 2(2Pic--O) B. 2(3Pic-O) B. 2(4Pic-O)
v(E-O)? 1620vs 1600vs 1600,1535vs 1085vs 1100vs 1215 1205vs 1160s 1208s 1620vs 1600vs 1590--40vs 1056vs 1100vs 1210vs 1210s 1160-70s 1200s
~(C--O) 1090-1100s, br 1100vs 1085-75s 1122--305 1100 1095--1100vs, br -1095 1115s 1120-10s 1090vs 1066-75 1117s 1100s 1070 1110m 1090-95s ll00s
v(O--Ti)
v(O ~ Ti)
605s 605s 615m 608s 635m ----622m 610m 585s -640s --625m --
405m -400sh 385w -415m -440w -430m 425m 400sh 455w 425w 422m 420m 400m --
u(Ti-CD 398vs, 385m, 350vs, 290m -380sh, 370vs, 360s, 290m 425s, 360m, 340vs, 330s, 320s 380vs, 365vs, 340vs, 320vs 380s, 345,285m 320vs,290s 390s, 380s, 340-20vs, 295s 400s, 380s, 270w 385s, 320vs 405m, 360s, 340s, 290m 415m, 375vs, 350--60s, 325m 435,390w, 340s, 330s 400sh, 380s, 360vs, 335s, 290m 40Ore,375vs, 350vs, 280s 400m, 380s, 360s 380s, 360vs, 290sh 40Ore,380s, 360vs, 290sh
u(Ti-CI--, Ti) 270m -280m, 245m 280m, 240m 280s, 245m ---270s, 250m 275m, 245m 280-90m, 245m 270w 280m ---
?E..O = C = O, P = O, N-O, A = Trichlorotitanium(IV) methoxide and B = Trichlorotitanium(IV) ethoxide. dimethylacetamide (DMA), tetramethyl urea (TMU), triphenyl phosphine oxide (TPPO), hexamethylphosphotriamide (HMPT), pyfidine-N-oxide (Py-O) and 2-, 3- and 4-picoline-N-oxides(PicO) produce solid adducts, the analyses (Table I) of which indicate them to have the general formulae Ti(OR)Cls.L and Ti(OR)CIy2L (where R = CH3, C2Hs and L = monodentate ligand). These complexes are hygroscopic. Some of them tend to polymerize on keeping long even in sealed tubes. Their insolubility or insumcient solubility in common organic solvents precludes conductance and molecular weight measurements. The changes in the IR spectra of the complexes in 4000-600 cm -I region is in accord with the coordination of these ligands through their oxygen atom to the titanium. For example, the v(C=O) of amides and tetramethylurea and u(P=O) of hexamethyiphosphotriamide and tetraphenylphosphine oxide and u(N=O) of the amine oxides shift to the lower frequency (Table 2) in the spectra of the complexes[7-10]. In these complexes the u(C--O) and u(Ti-O) are present around 1100 and 600cm -1 respectively (Table 2). In the low frequency region, the spectra of all the complexes show bands around 380 and 360cm -~ (Table 2) and this is the region where u(Ti--Cl) in 6-coordinate titanium absorbs[ll, 12]. Such spectral features are expected for 1:2 adducts. These 1:1 adducts, therefore may be considered to be dimeric either through alkoxy bridges analogous to that shown to exist in Ti(OR)2CI213 or chlorine bridges [14,15]. The presence of absorption bands at 270 and 250cm -1 in some of the 1:1 complexes (Table 2) are nearly at the same spectral region as reported in the earlier work[14,15] for the complexes (TiCI4.POCI3)2 and [(C2Hs)4N]+ (Ti2Clg)-, for which the bridging Ti-CI stretching vibrations were observed around 270 and 240cm -~. The complexes also show non-ligand bands around 400cm -~ which may be assigned to O--,Ti vibrations [161.
Department of Chemistry Pan]ab University Chandigarh-160 014 India
R.C. PAUL P . K . GUPTA S.L. CHADHA
~CES 1. A. Anagnostopoulos, Chim. Chron. 32, 1 (1967). 2. Adalbert Feltz, Z. Anorg. Allg. Chem. 334, 186 (1964-65). 3. D. C. Bradley, D. C. Hancock and W. Wa~llaw, J. Chem. Soc. 2773 (1952). 4. V. V. Yastrebov and A. J. Chernyshev, Zhur ObshcheiKhim.
40, 604 (1970). 5. R. J. H. Chtrk, The Chemistry of Titanium and Vanadium, Elsevier Publication Co., London, p. 301 (1968). 6. A. I. Vogel, A Text Book of Inorganic Quantitative Analysis, p. 461. Longmans, London (1961). 7. N. M. Karayannis, A. N. Speca, L. L. Pytlewski and M. M. Labes, J. Less Common Metals 22, 117 (1970). 8. R. C. Paul, H. S. Makhni, P. Singh and S. L. Chadha, J. Inorg. NucL Chem. 32, 2141 (1970); Z. Aaorg. Allg. Chem. 377, 108 (1970). 9. R. C. Paul, Harmeet Madan and S. L. Chadha, 1. Inorg. Nucl. Chem. 36, 737 (1974);37, 447 (1975). 10. R. C. Paul, Vecna Nagpal and S. L. Chedha, Inorg. Chim. Acta. 6, 335 (1972). 11. R.J.H. Clark and W. Erriogton, J. Chem. $oc. (A), 258 (1967). 12. R. J. H. Clark, Spectrochim. Acta 21,955 (1965). 13. H. Hoppe and W. Haase, Acta Cryst. B24, 281 (1968). 14. C. I. Branden and I. Lindqvist, Acta Chem. $cand. 14, 726 (1906). 15. R. J. H. Clark and M. A. Coles, J. Chem. $oc. (Dalton Trans.) 1463 (1974). 16. R. C. Paul, Subash Seed and S. L. Chadha, J. Inorg. Nucl. Chem. 33, 2703 (1971).
]. morg.mud.Chem.,1977,Vol.39,pp. 1855-1857. PergamonPress. Printedin GreatBritain
Antimony and bismuth trihaHde complexes o! dithiomalonamide, N,N'-dimethyl. and N,N'diphenyi-dithiomalonamide (Received 24 February 1976) Some antimony and bismuth trihalide complexes of di- X = CI, Br, I) (L': M = Sb, X = CI, Br; M = Bi, X = CI, Br, I) and thiomalonamide (L'), N,N'-dimethyl- (L") and N,N'-diphenyl- 1.5L'MX3 (M = Sb, X = I; M = Bi, X -- Br). The ligands are S,Sdithiomalonamide (L') have been isolatedwith stoichiometries: coordinated to the metal. Two IR v(MS) bands and some massL.MX3 (L':M = Sb, X = CI, Br; M = Bi, X = CI) (L': M = Sb, Bi, dependent bands assignable to (MX) modes are observed.
1856
Notes
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Notes INTRODUCTION
With transition metal ions dithiomalonamide and N,N'-disubstituted dithiomalonamides form neutral complexes in neutral solution and cationic complexes in acidic solution[l-3]. Dithiomalonamides are structurally analogous to //-dithioketones and may give metal complexes containing six-membered rings either they are S,S- or S,N- or N,N-coordinates. We have investigated in this work the complexes of antimony and bismuth trihalides with dithiomalonamide (Hdtma), N,N'-dimethyl(Me2Hdtma) and N,N'-diphenyl-dithiomalonamide (Ph2Hdtma). EXPERIMENTAL Hdtma was prepared by the method of Taylor et aL[4], Ph2Hdtma by the method of Barnikow et al.[5] and Me2Hdtma by sulphurizing with P2S5 the N,N'-dimethylmalonamide prepared by the method of Backes et al. [6]. All the reagents were of the best chemical grade. The Hdtma-SbX3 complexes were prepared by mixing equimolecular solutions of the halide in the minimum volume of dichloromethane (DCM) and of the ligand in the minimum volume of acetone. The chloride and bromide solutions were evaporated to dryness in vacuo and the solid residue washed with ethyl ether (EhO) for the chloride and with ethanol and Et20 for the bromide. The iodide was precipitated with ethanol from the solution evaporated to a small volume and was washed with EhO. The Hdtma-BiX 3 complexes immediately precipitate by slowly adding a solution of 2mM of the ligand in the minimum volume of acetone to a solution of 4 mM of the halide in 200 ml of DCM; the compounds were washed with Et20. The Me2Hdtma- and Ph2Hdtma halide complexes, except those indicated below, immediately precipitate by adding a solution of 1 mM of the ligand to 1 mM of the halide in the minimum volume of DCM and were washed with DCM and EhO. The Me2Hdtmaiodide complexes precipitate by adding Et20 to a mixture of a solution of I mM L in the minimum votume of DCM and a solution of 2mM of the iodide in the minimum volume of acetone, and were washed with Et20. The Ph2Hdtma-BiI3 complex was obtained as a voluminous precipitate by mixing the solutions of 1 mM BiI3 in the minimum volume of 1 : 1 benzeneethanol and of 1 mM L in the minimum volume of benzene, adding Et20 until incipient turbidity and cooling at 0°C for 1 hr. Carbon and hydrogen were determined by elemental analysis and bismuth with EDTA. Molar conductivities were determined at room temperature with a WTW conductivity bridge. IR spectra were recorded in KBr disks (4000-250cm-1) or in Nujol mulls on polythene (600-250cm -I) with a Perkin-Elmer 521 spectrophotometer and in Nujol mulls on polythene (400-60 cm-1) with an Hitachi FIS3 spectrophotometer. Analyses, found: % (calcd. %). Hdtma = L: L.SbCI3, C, 11.08 (9.94); H, 1.87 (1.67); L.SbBr3, C, 8.12 (7.26); H, 1.53 (1.22); 1.5L.SbI3, C, 7.38 (7.67); H, 1.16 (1.13); L.BiCI3, C, 8.75 (8.01), H, 1.38 (1.34); 1.5L.BiBr3, C, 7.84 (8.31), H, 1.89 (1.40). Me2Hdtma = L': L'.SbCI3, C, 15.21 (15.37), H, 2.60 (2.58); L'.SbBr3; C, 11.38 (11.46); H, 1.78 (1.92); L'.SbI3; C, 8.55 (9.03); H, 1.77 (1.52): L"BiCI3; C, 12.52 (12.56); H, 2.40 (2.11): L'.BiBr3; C, 10.26 (9.82); H, 1.64 (1.65); Bi, 34.52 (34.20); L"BiI3; C, 8.35 (7.98). Ph2Hdtma=L": L".SbCI3; C, 35.03 (34.67); H, 3.00 (2.74); L".SbBr 3, C, 27.83 (27.78); H, 2.35 (2.18); L".BiCI3, C, 30.00 (29.92), H, 2.50 (2.35), Bi, 34.62 (34.74); L"-BiBr3;C, 24.50 C, 24.49): H, 2.18 (1.92); L".BiI3; C, 20.95 (21.32); H, !.68 (1.67), Bi, 23.98 (24.76). RI~ULTS AND DISCUSSION
The complexes of antimony and bismuth trihalides with dithiomalonamide and its N,N'-dimethyl- and N,N'-diphenylderivatives have mostly a 1:1 ligand:halide ratio. Only Hdtma forms 1.5:1 complexes with SbI3 and BiBr3. Molar conductivities in dimethylformamide and in nitrobenzene show a certain tendency to ionic dissociation which is highest for the Me2Hdtma complexes of the iodides. The infrared spectra (Table 1) show that the ligands are S,Scoordinated to the metal. Their v(CN) and v(CS) bands are shifted to higher and lower frequencies, respectively, in
1857
agreement with an increase and a decrease in double bond character of the C-N and C-S bonds, respectively, in the complexes, Two v(MS) bands are observed, as expected for a ligand S,S-chelation, at frequencies which are in agreement with the values observed for the dithiomalonamide complexes with other metals[l,3] and for the antimony and bismuth complexes of S,S-chelating ligands [7, 8]. It is remarkable that the frequency of the first v(MS)band decreases, for both series of metal complexes, in the order Hdtma > Me2Hdtma > Ph2Hdtma, that is in the reverse order of the steric hindrance of the ligands. The mass-sensitive bands assignable to (MX) vibrations lie in the range of other literature values for the trihalides [9,10] and their complexes [11-13]. Because of the great number and the possible superposition of the far IR bands and of the fact that some spectra were rather weak it is not sure that all the (MX) band could be identified. The values of the frequency (cm-x) ratios Sb CI:Br:I Me2Hdtma.MX3 335:230:172= 1:0.69:0.51 318:222:162= 1:0.70:0.51 250:190:136 = 1:0.76:0.54 329:226= 1:0.69 Ph2Hdtma.MX3 299:204=1:0.68 230:160=1:0.70 194:145 = 1:0.75
Bi CI:Br 253:168= 1:0.67 214:148= 1:0.69 184:120= 1:0.65 252:166= 1:0.66 230:145=1:0.63 176:115=1:0.65
indicate that, for each metal, these L.MX 3 complexes have similar coordination structures[14], which may be of the square pyramid type, with the stereochemically active electron pair in the sixth position[15].
Acknowledgement--This work was supported by financial aid from the Consiglio Nazionale delle Richerche of Italy. GIAN CARLO PELLACANI GIORGIO PEYRONEL WANDA MALAVASI LEDI MENABUE Istituto di Chimica Generale e lnorganica University of Modena 41100 Modena Italy REFERENCES 1. G. Peyronel, G. C. Pellacani, G. Benetti and G. Pollacci, J. Chem. Soc. (Dalton Trans.) 879 (1973). 2. G. C. Pellacani, G. Peyronel and W. Malavasi, lnorg. Chim. Acta 8, 49 (1974). 3. G. C. Pellacani and W. Delle Donne Malavasi, J. Inorg. Nucl. Chem. 37, 477 (1975). 4. E. C. Taylor and J. A. Zoitewicz, Y. Am. Chem. Soc. 82, 2656 (1960). 5. G. B. Barnikow, V. Kath and D. Richter, £ prakt. Chem. 30, 63 (1965). 6. J. V. Backes, R. W. West and M. A. Witeley, Y. Chem. Soc. 119, 359 (1921). 7. M. Ikram and D. B. Powell, Spectrochim. Acta, 28A, 59 (1972). 8. G. Peyronel, A. C. Fabretti and G. C. Pellacani, Spectrochim. Acta 30A, 1723 (1974). 9. E. Chemouni, Y. Inorg. Nuel. Chem. 33, 2317 (1971). 10. T. R. Manley and D. A. Williams, Spectrochim. Acta 21, 1773 (1965). 11. S. T. Yuan and S. K. Madan, lnorg. Chim. Acta 6, 463 (1972). 12. R. P. Oertel, Spectrochim. Acta 23A, 659 (1970). 13. A. Ouchi, T. Takeuchi and I. Taminaga, Bull. Chem. Soc. Japan 43, 2840 (1970). 14. A. M. Brodie and C. J. Wilkins, Inorg. Chim. Acta 8, 13 (1974). 15. P. Bertan and S. K. Madan, J. Inorg Nucl. Chem. 36, 983 (1974).
Notes Table 2. Characteristicinfraredvibrations(cm -~) of the complexes of tn'chlortitanium(IV)alkoxides with some oxygendonor iigands Complex A. DMF A. DMA A. TMU A. TPPO A. HMPT A. 2Py-O A. 2(2Pic-O) A. 2(3PiC-O) A. 2(4Pic-O) B. DMF B. DMA B. TMU B. TPPO B. HMPT B. 2Py-O B. 2(2Pic--O) B. 2(3Pic-O) B. 2(4Pic-O)
v(E-O)? 1620vs 1600vs 1600,1535vs 1085vs 1100vs 1215 1205vs 1160s 1208s 1620vs 1600vs 1590--40vs 1056vs 1100vs 1210vs 1210s 1160-70s 1200s
~(C--O) 1090-1100s, br 1100vs 1085-75s 1122--305 1100 1095--1100vs, br -1095 1115s 1120-10s 1090vs 1066-75 1117s 1100s 1070 1110m 1090-95s ll00s
v(O--Ti)
v(O ~ Ti)
605s 605s 615m 608s 635m ----622m 610m 585s -640s --625m --
405m -400sh 385w -415m -440w -430m 425m 400sh 455w 425w 422m 420m 400m --
u(Ti-CD 398vs, 385m, 350vs, 290m -380sh, 370vs, 360s, 290m 425s, 360m, 340vs, 330s, 320s 380vs, 365vs, 340vs, 320vs 380s, 345,285m 320vs,290s 390s, 380s, 340-20vs, 295s 400s, 380s, 270w 385s, 320vs 405m, 360s, 340s, 290m 415m, 375vs, 350--60s, 325m 435,390w, 340s, 330s 400sh, 380s, 360vs, 335s, 290m 40Ore,375vs, 350vs, 280s 400m, 380s, 360s 380s, 360vs, 290sh 40Ore,380s, 360vs, 290sh
u(Ti-CI--, Ti) 270m -280m, 245m 280m, 240m 280s, 245m ---270s, 250m 275m, 245m 280-90m, 245m 270w 280m ---
?E..O = C = O, P = O, N-O, A = Trichlorotitanium(IV) methoxide and B = Trichlorotitanium(IV) ethoxide. dimethylacetamide (DMA), tetramethyl urea (TMU), triphenyl phosphine oxide (TPPO), hexamethylphosphotriamide (HMPT), pyfidine-N-oxide (Py-O) and 2-, 3- and 4-picoline-N-oxides(PicO) produce solid adducts, the analyses (Table I) of which indicate them to have the general formulae Ti(OR)Cls.L and Ti(OR)CIy2L (where R = CH3, C2Hs and L = monodentate ligand). These complexes are hygroscopic. Some of them tend to polymerize on keeping long even in sealed tubes. Their insolubility or insumcient solubility in common organic solvents precludes conductance and molecular weight measurements. The changes in the IR spectra of the complexes in 4000-600 cm -I region is in accord with the coordination of these ligands through their oxygen atom to the titanium. For example, the v(C=O) of amides and tetramethylurea and u(P=O) of hexamethyiphosphotriamide and tetraphenylphosphine oxide and u(N=O) of the amine oxides shift to the lower frequency (Table 2) in the spectra of the complexes[7-10]. In these complexes the u(C--O) and u(Ti-O) are present around 1100 and 600cm -1 respectively (Table 2). In the low frequency region, the spectra of all the complexes show bands around 380 and 360cm -~ (Table 2) and this is the region where u(Ti--Cl) in 6-coordinate titanium absorbs[ll, 12]. Such spectral features are expected for 1:2 adducts. These 1:1 adducts, therefore may be considered to be dimeric either through alkoxy bridges analogous to that shown to exist in Ti(OR)2CI213 or chlorine bridges [14,15]. The presence of absorption bands at 270 and 250cm -1 in some of the 1:1 complexes (Table 2) are nearly at the same spectral region as reported in the earlier work[14,15] for the complexes (TiCI4.POCI3)2 and [(C2Hs)4N]+ (Ti2Clg)-, for which the bridging Ti-CI stretching vibrations were observed around 270 and 240cm -~. The complexes also show non-ligand bands around 400cm -~ which may be assigned to O--,Ti vibrations [161.
Department of Chemistry Pan]ab University Chandigarh-160 014 India
R.C. PAUL P . K . GUPTA S.L. CHADHA
~CES 1. A. Anagnostopoulos, Chim. Chron. 32, 1 (1967). 2. Adalbert Feltz, Z. Anorg. Allg. Chem. 334, 186 (1964-65). 3. D. C. Bradley, D. C. Hancock and W. Wa~llaw, J. Chem. Soc. 2773 (1952). 4. V. V. Yastrebov and A. J. Chernyshev, Zhur ObshcheiKhim.
40, 604 (1970). 5. R. J. H. Chtrk, The Chemistry of Titanium and Vanadium, Elsevier Publication Co., London, p. 301 (1968). 6. A. I. Vogel, A Text Book of Inorganic Quantitative Analysis, p. 461. Longmans, London (1961). 7. N. M. Karayannis, A. N. Speca, L. L. Pytlewski and M. M. Labes, J. Less Common Metals 22, 117 (1970). 8. R. C. Paul, H. S. Makhni, P. Singh and S. L. Chadha, J. Inorg. NucL Chem. 32, 2141 (1970); Z. Aaorg. Allg. Chem. 377, 108 (1970). 9. R. C. Paul, Harmeet Madan and S. L. Chadha, 1. Inorg. Nucl. Chem. 36, 737 (1974);37, 447 (1975). 10. R. C. Paul, Vecna Nagpal and S. L. Chedha, Inorg. Chim. Acta. 6, 335 (1972). 11. R.J.H. Clark and W. Erriogton, J. Chem. $oc. (A), 258 (1967). 12. R. J. H. Clark, Spectrochim. Acta 21,955 (1965). 13. H. Hoppe and W. Haase, Acta Cryst. B24, 281 (1968). 14. C. I. Branden and I. Lindqvist, Acta Chem. $cand. 14, 726 (1906). 15. R. J. H. Clark and M. A. Coles, J. Chem. $oc. (Dalton Trans.) 1463 (1974). 16. R. C. Paul, Subash Seed and S. L. Chadha, J. Inorg. Nucl. Chem. 33, 2703 (1971).
]. morg.mud.Chem.,1977,Vol.39,pp. 1855-1857. PergamonPress. Printedin GreatBritain
Antimony and bismuth trihaHde complexes o! dithiomalonamide, N,N'-dimethyl. and N,N'diphenyi-dithiomalonamide (Received 24 February 1976) Some antimony and bismuth trihalide complexes of di- X = CI, Br, I) (L': M = Sb, X = CI, Br; M = Bi, X = CI, Br, I) and thiomalonamide (L'), N,N'-dimethyl- (L") and N,N'-diphenyl- 1.5L'MX3 (M = Sb, X = I; M = Bi, X -- Br). The ligands are S,Sdithiomalonamide (L') have been isolatedwith stoichiometries: coordinated to the metal. Two IR v(MS) bands and some massL.MX3 (L':M = Sb, X = CI, Br; M = Bi, X = CI) (L': M = Sb, Bi, dependent bands assignable to (MX) modes are observed.
1856
Notes
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~
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8
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T
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Notes INTRODUCTION
With transition metal ions dithiomalonamide and N,N'-disubstituted dithiomalonamides form neutral complexes in neutral solution and cationic complexes in acidic solution[l-3]. Dithiomalonamides are structurally analogous to //-dithioketones and may give metal complexes containing six-membered rings either they are S,S- or S,N- or N,N-coordinates. We have investigated in this work the complexes of antimony and bismuth trihalides with dithiomalonamide (Hdtma), N,N'-dimethyl(Me2Hdtma) and N,N'-diphenyl-dithiomalonamide (Ph2Hdtma). EXPERIMENTAL Hdtma was prepared by the method of Taylor et aL[4], Ph2Hdtma by the method of Barnikow et al.[5] and Me2Hdtma by sulphurizing with P2S5 the N,N'-dimethylmalonamide prepared by the method of Backes et al. [6]. All the reagents were of the best chemical grade. The Hdtma-SbX3 complexes were prepared by mixing equimolecular solutions of the halide in the minimum volume of dichloromethane (DCM) and of the ligand in the minimum volume of acetone. The chloride and bromide solutions were evaporated to dryness in vacuo and the solid residue washed with ethyl ether (EhO) for the chloride and with ethanol and Et20 for the bromide. The iodide was precipitated with ethanol from the solution evaporated to a small volume and was washed with EhO. The Hdtma-BiX 3 complexes immediately precipitate by slowly adding a solution of 2mM of the ligand in the minimum volume of acetone to a solution of 4 mM of the halide in 200 ml of DCM; the compounds were washed with Et20. The Me2Hdtma- and Ph2Hdtma halide complexes, except those indicated below, immediately precipitate by adding a solution of 1 mM of the ligand to 1 mM of the halide in the minimum volume of DCM and were washed with DCM and EhO. The Me2Hdtmaiodide complexes precipitate by adding Et20 to a mixture of a solution of I mM L in the minimum votume of DCM and a solution of 2mM of the iodide in the minimum volume of acetone, and were washed with Et20. The Ph2Hdtma-BiI3 complex was obtained as a voluminous precipitate by mixing the solutions of 1 mM BiI3 in the minimum volume of 1 : 1 benzeneethanol and of 1 mM L in the minimum volume of benzene, adding Et20 until incipient turbidity and cooling at 0°C for 1 hr. Carbon and hydrogen were determined by elemental analysis and bismuth with EDTA. Molar conductivities were determined at room temperature with a WTW conductivity bridge. IR spectra were recorded in KBr disks (4000-250cm-1) or in Nujol mulls on polythene (600-250cm -I) with a Perkin-Elmer 521 spectrophotometer and in Nujol mulls on polythene (400-60 cm-1) with an Hitachi FIS3 spectrophotometer. Analyses, found: % (calcd. %). Hdtma = L: L.SbCI3, C, 11.08 (9.94); H, 1.87 (1.67); L.SbBr3, C, 8.12 (7.26); H, 1.53 (1.22); 1.5L.SbI3, C, 7.38 (7.67); H, 1.16 (1.13); L.BiCI3, C, 8.75 (8.01), H, 1.38 (1.34); 1.5L.BiBr3, C, 7.84 (8.31), H, 1.89 (1.40). Me2Hdtma = L': L'.SbCI3, C, 15.21 (15.37), H, 2.60 (2.58); L'.SbBr3; C, 11.38 (11.46); H, 1.78 (1.92); L'.SbI3; C, 8.55 (9.03); H, 1.77 (1.52): L"BiCI3; C, 12.52 (12.56); H, 2.40 (2.11): L'.BiBr3; C, 10.26 (9.82); H, 1.64 (1.65); Bi, 34.52 (34.20); L"BiI3; C, 8.35 (7.98). Ph2Hdtma=L": L".SbCI3; C, 35.03 (34.67); H, 3.00 (2.74); L".SbBr 3, C, 27.83 (27.78); H, 2.35 (2.18); L".BiCI3, C, 30.00 (29.92), H, 2.50 (2.35), Bi, 34.62 (34.74); L"-BiBr3;C, 24.50 C, 24.49): H, 2.18 (1.92); L".BiI3; C, 20.95 (21.32); H, !.68 (1.67), Bi, 23.98 (24.76). RI~ULTS AND DISCUSSION
The complexes of antimony and bismuth trihalides with dithiomalonamide and its N,N'-dimethyl- and N,N'-diphenylderivatives have mostly a 1:1 ligand:halide ratio. Only Hdtma forms 1.5:1 complexes with SbI3 and BiBr3. Molar conductivities in dimethylformamide and in nitrobenzene show a certain tendency to ionic dissociation which is highest for the Me2Hdtma complexes of the iodides. The infrared spectra (Table 1) show that the ligands are S,Scoordinated to the metal. Their v(CN) and v(CS) bands are shifted to higher and lower frequencies, respectively, in
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agreement with an increase and a decrease in double bond character of the C-N and C-S bonds, respectively, in the complexes, Two v(MS) bands are observed, as expected for a ligand S,S-chelation, at frequencies which are in agreement with the values observed for the dithiomalonamide complexes with other metals[l,3] and for the antimony and bismuth complexes of S,S-chelating ligands [7, 8]. It is remarkable that the frequency of the first v(MS)band decreases, for both series of metal complexes, in the order Hdtma > Me2Hdtma > Ph2Hdtma, that is in the reverse order of the steric hindrance of the ligands. The mass-sensitive bands assignable to (MX) vibrations lie in the range of other literature values for the trihalides [9,10] and their complexes [11-13]. Because of the great number and the possible superposition of the far IR bands and of the fact that some spectra were rather weak it is not sure that all the (MX) band could be identified. The values of the frequency (cm-x) ratios Sb CI:Br:I Me2Hdtma.MX3 335:230:172= 1:0.69:0.51 318:222:162= 1:0.70:0.51 250:190:136 = 1:0.76:0.54 329:226= 1:0.69 Ph2Hdtma.MX3 299:204=1:0.68 230:160=1:0.70 194:145 = 1:0.75
Bi CI:Br 253:168= 1:0.67 214:148= 1:0.69 184:120= 1:0.65 252:166= 1:0.66 230:145=1:0.63 176:115=1:0.65
indicate that, for each metal, these L.MX 3 complexes have similar coordination structures[14], which may be of the square pyramid type, with the stereochemically active electron pair in the sixth position[15].
Acknowledgement--This work was supported by financial aid from the Consiglio Nazionale delle Richerche of Italy. GIAN CARLO PELLACANI GIORGIO PEYRONEL WANDA MALAVASI LEDI MENABUE Istituto di Chimica Generale e lnorganica University of Modena 41100 Modena Italy REFERENCES 1. G. Peyronel, G. C. Pellacani, G. Benetti and G. Pollacci, J. Chem. Soc. (Dalton Trans.) 879 (1973). 2. G. C. Pellacani, G. Peyronel and W. Malavasi, lnorg. Chim. Acta 8, 49 (1974). 3. G. C. Pellacani and W. Delle Donne Malavasi, J. Inorg. Nucl. Chem. 37, 477 (1975). 4. E. C. Taylor and J. A. Zoitewicz, Y. Am. Chem. Soc. 82, 2656 (1960). 5. G. B. Barnikow, V. Kath and D. Richter, £ prakt. Chem. 30, 63 (1965). 6. J. V. Backes, R. W. West and M. A. Witeley, Y. Chem. Soc. 119, 359 (1921). 7. M. Ikram and D. B. Powell, Spectrochim. Acta, 28A, 59 (1972). 8. G. Peyronel, A. C. Fabretti and G. C. Pellacani, Spectrochim. Acta 30A, 1723 (1974). 9. E. Chemouni, Y. Inorg. Nuel. Chem. 33, 2317 (1971). 10. T. R. Manley and D. A. Williams, Spectrochim. Acta 21, 1773 (1965). 11. S. T. Yuan and S. K. Madan, lnorg. Chim. Acta 6, 463 (1972). 12. R. P. Oertel, Spectrochim. Acta 23A, 659 (1970). 13. A. Ouchi, T. Takeuchi and I. Taminaga, Bull. Chem. Soc. Japan 43, 2840 (1970). 14. A. M. Brodie and C. J. Wilkins, Inorg. Chim. Acta 8, 13 (1974). 15. P. Bertan and S. K. Madan, J. Inorg Nucl. Chem. 36, 983 (1974).