N-thiocarbamoyl-N′-carbamoyl hydrazine derivatives and their metal complexes

J. inorg,nucl.Chem., 1966,Vol.28, pp. 1633to 1644. PergamonPre~tLtd. Printedin NorthernIreland

N-THIOCARBAMOYL-N'-CARBAMOYL HYDRAZINE DERIVATIVES AND THEIR METAL COMPLEXES A. DUTTA AHMED* and P. K. MANDAL Inorganic Chemistry Division, Indian Association for the Cultivation of Science, Calcutta-32, India (Received 23 November 1965)

~ - - A study of N-thioearbamoyl-N'-carbamoylhydrazine derivatives as complexing ligands and their Ni, Cu, Zn and Cd complexes is described. The metals form 1 : 1 chelates with the ligands. One compound with formula Cu(I) (C~J-Is.NH.CS.NH.NH.C0.NH~)sC1 is also described. Ultraviolet and i.r. spectra of the ligands and the metal complexes and the magnetic properties of the latter are discussed. Structures for the metal complexes are proposed.

JENSEN and MIQUEL¢1) have described nickel complexes of N-thiobenzoyl-N'-(carbamoyl, thiocarbamoyl) hydrazine. Metal chelates of N-N'-di(allylthioearbamoyl) hydrazine have also been described from this laboratory t2.a). Recently ABLOV and G~R~LEU t~ have reported metal salts and complexes of a number of thiosemicarbazides and thiosemicarbazones. Now, it might be of interest to make a similar study with N.thiocarbamoyl N'.carbamoyl hydrazine derivatives. These compounds enolize and function as dibasic and possibly tetradentate ligands just as N-N'-di(thiocarbamoyl) hydrazine derivatives do. Metal chelates with these ligands have not been previously described. The present communication describes three ligands and their nickel, copper, zinc and cadmium chelates, of the same general formulae: (i) Ligand I: N-phenylthiocarbamoyl-N'-carbamoyl hydrazine CoHsNH-CS.NHNH.CO.NH z (ii) Ligand II: N-thiocarbamoyl-N'-phenylcarbamoyl hydrazine HzN.CS.NHNH-CO.NHCoH 5 (iii) Ligand III: N-allylthiocarbamoyl-N'-carbamoyl hydrazine CaHsNH.CS.NHNH.CO.NH 2 EXPERIMENTAL Preparation of Ligand I

The ligand was prepared from potassium cyanate, 4-phenylthiosemicarbazide and hydrochloric acid or from semicarbazide hydrochloride (0.1 mole), sodium carbonate and phenyl-isothiocyanat¢ as described by AgNOT et aL ~s~ The ligand was purified by repeated recrystallization from aqueous ethanol and analysed (m.p. 196°C). * To whom correspondence concerning this paper should be addressed. txJ K. A. JENSENand J. F. MIQUEL,Acta chem. scand. 6, 189 (1952). n~ N. K. DuTr and K. P. SEN SARMA, Analytica. chim. Acta 15, 21 (1956). cs~A. D u r r a ~ and S. N. DHAR, Sci. & Cult. 28, 540 (1962). ~'~ A. V. AnLOVand N. V. G~V.LEU, Zh. neorg. Khim. 9, 85 (1964) (eng. edn. p. 46). ~5~F. ARNO% E. MILI)~ and F. TSC~NSCHL~, Ber. dr. chem. Ges. 5513, 341 (1922). 1633

21"83 (22"01)

24.39 (23"60)

23"33 (23"39)

23 "08 (23-39)

25"28 (25.05)

Ni-Ligand IIb

Ni-Ligand III b

Cu-Ligand I b

Cu-Ligand H b

Cu-Ligand

(20"62)'

22.24 (22-09)

(20.62)

(11-79)

12.91 (12.62)

20"94

(20.62)

20-53

21 "75 (22-52)

21.13 (21"00)

11-97

11"68 (11-79)

12"83 (12-87)

(I 1"99)

11-10

19"72 (19-67)

Ni-Ligand I b

11.85 (11.24)

32.10 (32-18)

Ligand HI

20.76

26-54 (26-67)

Nitrogen

Ligand II

Sulphur 26"14 (26.67)

Metal

Ligand I

Compound

33-78 (34.48)

46.11 (45.72)

45"80 (45.72)

7"15 (7"10)

6"99 (7.24)

6"69 (6"67)

HsO e

5.79 (5.75)

4.93 (4.76)

4"89 (4-76)

Hydrogen

Others Formula

CUO1)(CsHsON,S)" 1 H,O

Cu(H)(CsHsON,S)

Cu(H)(CsHsON,S)

Ni(II)(CsHsON,S)" 1 HsO

Ni(II)(CsHaON,S)

Ni(II)(CsHsON4S)'I HsO

CsHioON~S

CsHloON,S

CsHxoOHN,S

LIGANDS A N D T H E I R COMPLEXES

Carbon

TABLE 1.--ANALYmSSo v

204°(d)

200°(d)

188°(d)

193°

218 °

196°

m.p./d.p. (uncorrected)

r~

ta,

.>

22.26 (22.44)

27.04 (27"54)

34-17 (35.09)

35.43 (35.09)

39"41 (39"53)

14"08 (14-21)

Zn-Ligand II °

Zn-Ligand IIIe

Cd-Ligand I a

Cd-Ligand II °

Cd-Ligand I l l e

Cu(I)-Ligand III a

15"02 (14.32)

11"65 (11-26)

10.03 (9-99)

9.94 (9.99)

13.32 (13"48)

10.92 (10.98)

11.10 (10.98)

18"23 (18"52)

16.98 (17.48)

17.39 (17.48)

22"81 (23.59)

19.30 (19.22)

19-12 (19"22) 6"15

8"24 (7"94)

Cl

6"21 (6.18)

(6"18)

ts~ Figures in parentheses are the required percentages tb~ Prepared by method A and/or B '~ Prepared by method A; preparation by method B needs extensive purification ca~ Prepared by method C ,e~ from dehydration cf~could not be determined.

22"71 (22-44)

Zn-Ligand 1 °

173°(d)

205-210°(d)

225°(d)

Cd(CaHaON4S)

Cd(CaHaON4S)

Cd(C6HsONIS)

196°(d)

200°(d)

Zn(CsHaON,S)

Cu(I)(CsHxoON,S),CI

220°(d)

200°(d)

Zn(CaHaON4S)" 1 HaO

Zn(CsHsON4S)q HtO

VI

t~

0

l-t

ea~

g

0"

1636

A. DUTTAAHMEDand P. K. MANDAL

Preparation of Ligand II The ligand was prepared from thiosemicarbazide and phenyl-isocyanate as described by FmSUND and SCHA~,U3F.Z~ te~ and was purified by repeated recrystallization from aqueous ethanol, and analysed (m.p. 218°(2).

Preparation of Ligand III The compound was prepared from semicarbazide hydrochloride and allyl-isothiocyanate as described by Busch and LoTz c7~ and was purified by repeated recrystallization from water and finally from ethanol and analysed (m.p. 193°C0.

Other chemicals Chemicals other than the ligands were of reagent grade. Ethanol and other solvents used for spectroscopic measurements were spectroscopically pure. cs~

Preparation of solutions of the ligands Thrice recrystallized ligands were used. For water solutions, warming to 60-70°C was allowed. Aqueous solutions of the ligands did not keep for more than 36 hr, decomposition being noted spectroscopically.

Preparation of metal chelates Three methods were used. (a) On addition of a soluble ammine complex of the metal (0.002 to 0.005 mole) to an aqueous solution or aqueous-ethanol solution of the ligand (0.008 to 0.020 mole), immediate precipitation occurred. The precipitate was heated on a water-bath for about half an hour, filtered, washed with dilute ammonia and finally with aqueous-ethanol, dried in a desiccator and analysed. The yield was quantitative. Co) On mixing an aqueous solution of the metal salt with an aqueous or aqueous--ethanol solution of the ligand in the same ligand/metal ratio as stated above, warming on waterbath, and on gradually raising the pH with a dilute solution of sodium bicarbonate, precipitation occurred. The precipitate was heated on a water bath for about half an hour, filtered, washed with warm water followed by aqueous-ethanol, dried in a desiccator and analysed. Yield was quantitative at proper pH values. (c) On addition of a hot ethanolic solution of metal chloride to a hot ethanolic solution of the ligand, pre~pitation occurred. The precipitate was washed with warm ethanol, desolvated and analysed.

Apparatus and measurements Absorptions in the u.v. and visible ranges were measured with a Hilger Uvispek, against the same solution minus the ligand as reference solution. Infra-red spectra were recorded with Perkin-Elmer models, 221 and 137B. Magnetic susceptibilities were measured with a Guoy Balance. The analyses of the compounds are shown in Table 1, along with their melting/decomposition points. The Amaxof u.v. spectra of ligands and complexes are summarized in Tables 2 and 4. Infrared bands are summarized in Table 3. The results of magnetic susceptibility measurements axe shown in Table 5. TAnLE 2.--Am~x (LOG0

96~o Ethanol 75~o Ethanol 50~o Ethanol 25yo Ethanol Water

VALUES OF LIGANDS IN AQUEOUS-ETHANOL soLUTION, IN

m/~

Ligand I

Ligand II

Ligand III

215(4.18), 235(4.12), 270(3.99) 214(4.22), 235 sh, 267 sh 212(4-27), 234 sh, 265sh

210(3.86), 245(4.39) 211(3-91), 245(4.41) 208(4.04), 243(4.42) 205(4.23), 242(4.40) 202(4-40), 242(4-38)

215(3.84), 245(4.13) 213(3.87), 244(4.12) 212(3.94), 243(4.12) 209(4.03), 241(4.13) a 240(4.14)

203(4.37), 245 sh

The Am,x value is at or below 200 m/~. I~UND and ScriAm~, Ber. dr. chem. Ges. 29, 2510 (1896). c7~M. BuscI~ and D. LOTZ, 3". Pr. 90, 270 (1914). c,~ A. WEISSaEROER,Editor, Techniqueof Organic Chemistry, Vol. VII. Interscience, New York (1955). ce~ M .

N-thiocarbamoyl-N'-carbamoyl hydrazine derivatives and their metal complexes RESULTS

AND

1637

DISCUSSION

The identification and characterization of the compounds have mainly b~en attempted from spectroscopic data. It is obvious though that due to the composite nature of the vibrations, interpretation and band assignment of the ligands and their metal derivatives is difficult.

The ligands The N-thiocarbamoyl-N'-carbamoyl hydrazine derivatives should have the following structure R--NH----C---NH--NH--C---NH--R'

II

II

S

O

It is possible that the ligands will exist in "keto" as well as "enol" forms, along with hydrogen-bonded and a number ofzwitter-ionic species. The effects are not necessarily of equal magnitude in both the "thiourea" and "urea" parts of the molecules. There is no band for OH or SH in the i.r. spectra of the ligands but hydrogen bonding and zwitterionic species are indicated, the complex nature and splitting of bands being observed in certain regions involving CS, CO and CN vibrations. Aqueous or alcohol solutions of the ligands show the existence of enol forms. Absorptions of a series of ligand-in-aqueous-ethanol solutions of differing water and ethanol proportions (Table 2 and a typical set of spectra in Fig. 1) as well as of isopropanol solution suggest tautomeric equilibria and zwitterionic species. Of the various resonating structures, the skeleton N - - ~ N - - N - - C - - N is most significant the delocalization of ~r-electrons lower the energy. The absorption maxima and extinction at 210 mp ascribed to this skeleton compares well with the data for CeHs--CH--N--N---CH--CeHs. ~°~ The usual changes in NCS band at 245 m/~ at higher pH's and in the absorption characteristics at 300 m/~ are also observed. The ligands are found to be dibasic. It may thus be concluded that the ligands form chelates through the following enolized form, R--NH~N--N~C--NH--R'

I

SH

L

OH

The observation agrees with previous finding¢1°-1~) in analogous cases. 1 :1

Metal chelates That the metal atoms are directly linked with the oxygen atoms can be proved by the absence of C----O and - - O H bands in the i.r. spectra. As far ~ts C-~-S is concerned there is some difference of opinion over the characteristic absorption region e.g. 1080 cm-1 ~ 1120 cm-1, ~13),~ 1400 cm- m i , m and ~ 730 cm-1. oz~ The latter two regions ~*~H. C. BARASY, E. A. BSAUDe and M. Pt~rr~, J. Chem. Soc. 1898 (1949). cxo~j. SA}r~srgoM, Acta chem. scand. 14, 1037 (1960). m} K. A. JmqseN and C. P~SRSeN, Acta chem. scand. 15, 1124 (1961). cm B. A. G ~ o P , t.s, R. L. SOMOIUAXand C. H. BAYLEY, Can. J. Chem. 39, 973 (1961). ix,} A. YAMAOUCHI,R. B. PEIqLAND, S. M x z U S ~ , T. J. LANE,C. CURRAN arid J. V. QUAGI.,IANO, J. Am. chem. Soc. 80, 527 (1958). cm E. Lnmmt, C. N. R. Rxo, C. N. PmL~, J. R~,~.AC[-IANDRANand R. D. HITeS, Can. J. Chem. 36, 801 (1958). cxs~j. E. STEWART,J. chem. Phys. 26, 248 (1957).

1565m

1310m

1310 s

1330s

1397sh

1315 s

1335 s

1420sh

1315 s

1335 s

1399sh

1310m

1345sh

1490m

1409ms

1350sh

1495 s

1495 s

1491 sh

1495 s

1525sh

1515 sb

1519m

1520s

1553 m

1540sh

1539ms 1515 s

1590 s 1550sh

1600s

1597sh

1575sh

1612m

1606 s

1615ms

3150m

3300sh

3350s

3500 m

Ligand

1612ms

2668 wb

2743m

3335 s

Ni

1655m

3280mb

3310mb

3557 mb

3500 mb

3375mb

Zn

Cu

Ligand I

1657 s

3185s

3244 s

3373m

Ligand

1325 sb

1490 s

1530sb

1550sb

1580s

1600 s

3220m

3350m

3500 m

Cu

L i g a n d II

1320sb

1510 s

1525m

1585 vs

1608 vs

2650mb

2720

3200s

3315 s

3435 m

3600 m

Zn

1325m

1390m

1505 w

1540s

1558sh

1592m

1608m

1515 m

1525m

1550m

1565m

1500sh

1535 s

1550sh?

1325 w

1522m

1555s

1580 s

1635m

1700s

2725 w

3140sb

3230 s

3300s

3346m

3368 m

3418m

3515

Cu0igandlII)2C1

1640m

1600 s

2730 m

3330 mb

3465 mb

Zn

Ligand HI

1672s 1600m

2720m

2770m

3300mb

3450 mb

Cu

1662 s

1692m

3160s

3315 s

3435 m

Ligand

TABLE 3.--SUMMARY OF i.r. BANDS OF LIGANDS AND THEIR CHELATES IN NUJOL IN c m -x

.>

890 w

880wb

835 w b

880m

820 wb

710m

680m

696sh

687ms

733m

740 m

705m

755m

690 m

715-730 m b

696ms

745 w

690s

720 s

750 s

710m 680 w

690 s

748m

720 m

750 s

710m 680m

685m

765m

710m

760sh

686 m

703 m

760 w

780 w

745m

760m

915 m

930 m

768 w

820m

915m

955 m

767m

835wb

885 w

910 w

950m

960m

982 m

lO00m

1040 w

1078 m

l130m

1160m

1230m

1292m

800 w

830m

910m

980m

980m

1030m

1060m

1145 s

1230m

1300s

785sh

835m

835 w

895 w 860m

895m

965m

960 m

965m 945m

990m

1035m

1080sh

1025 m ?

1070m

1027m

862 v w

910 v w

?

1026m

1070m

1145 m

1220m

1295m

795 v w

750m

930 v w

930 v w

930 v w

? 1041 m

l120m

l150m

1225m

1290m

795 w

926 w

962 w

960m

965m

985 w

950m

1020m

1005 w

990sh

1005 w

1070m

1030m

1030m

1025 w

1076m

070m

I074m

1094sh

ll50sh

l150m

l130m

ll30ms

1122 m

ll50wb

ll50sh

l145mb

1165sh

1135m

1222 m 1160 w

1220m

1220m

1215m

1240s l170m

1235m l170m

1260 w

1255sh?

1256sh?

1250sh?

1300 b

1215m

1300 s b

1256m

1296 m

1290sh?

1290sh?

1290m

ou

g

8

Z

1640

A. DUTTAAHM~ andP. K. MANDAL

LIGAND I

fir ~|1

I.o

II

rl

IN

,.,.~.~.o~ "'/" " ,o.~o ,,

|tl

I~I

o =.

O5

2OO

250 3OO WAVELENGTH (m/.c)--~

350

F]Q. 1.--Absorptions of N-allylthiocarbamoyl-N'-carbamoylhydrazine; 9.060 x 10-' M. BO

60~. ,, .o 0..,,,°,,..°.~

5G

\"

w U Z 4[ II-

4C

Z

3C

p--

20

I0

0 3600

I 3500

I 3400

I 3300

WAVELENGTH 1:;IO. 2a

I 3200

I 3lOG

3000 cn'T'

N-thiocarbamoyl-N-carbamoylhydrazine derivatives and their metal complexes

1641

{]

('l I ,

I/V/ •

v

....

r..-;

.

: ",./

/

/',i -i:/ 30 " U

:

: I: ¢6

\/

,

V

~;.

,o

1700

I 1600

I 1500

I 1400

I 1300

I 1200

I I100

I I000

I 900

I 800

I 700

6o(

cm

WAVELENGTH

Fxo. 2b.--I.R. spectra of Ligand HI ( ) and its Cu chelate (- . . . . . ), its Zn chelate ( . . . . . . . . . of Cu (Ligand HI)= C1 ( . . . . . . . -).

TABL~4.--2m=x V~LU~SOF C'H~ATESIN ETHANOL, IN m ~ Ligand I Ni Cu Zn Cd Cus b

215 sh, 238, 260, 282 sh 219 245 sh 220, 238, 250 sh, 265, 282 sh 220, 240, 255 sh, 282 sh

Ligand ]I

Ligand HI

215, 242, 270 sh 216, 220 sh, 280 sh 220, 245 220, 245, 250 sh 207, 239 205(4.38), 245(4.25), 280(4.12) 207(4.30), 245(4.30), 278 sh 206(4.08), 240(4.09) 214 sh, 255 215, 255 210 sh, 250 220, 245

= Cu" (Ligand I]T)aCI in water. b )'max (log e) of Ligand I at pH 11.02 (pH > pK,), of Ligand II at pH 10-87 (pH > pK0 and of Ligand lII at pH 10.50 (pH ~ pK0.

) and

1642

A. DUTI'A AHMED and P. K. M A ~ A ~

"-- 0

0

Z 0

8

0

u')

iln

0

~

X

!

Z 0 ".~

L 8N

0

~

~2

u.

"0"0 O

"O 0

•

u. o

13

q

,~

z

u

O

6

I O t.f3

I t.n f~

O

0 "(0"O

8

N-thiocarbamoyl-N'-carbamoyl hydrazine derivatives and their metal complexes

1643

are preferred, tm although some CN interactions are always likely to be present. However, bands present in the ligands in this region are absent in the chelates, and their absence is taken as evidence of metal-sulphur linkages. It is believed that certain new bands o f the chelates in the 800--1000 cm -~ region are overtones of metaloxygen/sulphur/nitrogen fundamentals. Similar to the azine group) xT~all the chelates show a band at ~-d600 cm -x. TABLE 5 . - - M A O N E T I C SUSCEPTIBILITIES OF COMPLEXES

Compounds Ni(CsHaON,S)'I HBO(I)~ Ni(CaH,ON,S) (II) Ni(CsHaON4S)'I HIO(IU) Cu(CaHsON4S) (I) Cu(CsHsON4S) (II) Cu(CsHBON,S)'I HtOOII) Cu(CsHloON,S)sCI(I~

XM(corrected) 2409.41 × 1211"34 × 2445.50 × 1142.44 × 1277"14 × 938.80 ×

10-6 10-6 10-e 10-6 10-6 10-6

(Diamagnetic correction) 100-61 × 10-6 90"14 × 10-e 76-70 × 10-6 90"14 × 10-e 90"14 × 10-6 76-70 × 10-6 Diamagnetic

/~B 2.39 1"70 2'41 1"65 1"75 1"50

a the numbers in the parenthesis denote the Ligand of which the compound is. The chelates are insoluble in organic solvents and in water, but the freshly prepared chelates are slightly soluble in organic solvents. Solutions for the measurements o f the u.v. absorption were prepared by refluxing freshly prepared chelates with ethanol. The insolubility is best explained by a polymeric structure. In such cases, the NH/NH~ of the (thio)carbamoyl group and either of the two nitrogen atoms of the azine group are capable of co-ordinating. The probability of co-ordination by both the nitrogen atoms of the azine group to the same metal atom is unlikely. Co-ordination of these two nitrogen atoms to two different metal atoms are possible in which case the ---OH and - - S H groups should be " t r a m " with respect to the N ~ N - - N - - - C - - N skeleton and each of them combine with two different metal atoms; if the two groups are "e/s" and attached to the same metal atom, co-ordination by one of the nitrogen atoms of the azine group to that metal atom will involve a strained four membered ring.* The other alternative is co-ordination by the nitrogen atoms of (thio)carbamoyl groups. All the bands in the region of 3 ~ in the chelates are broad and diffuse suggesting hydrogen bonding. Except the amide I bands observed near 1650 cm -1 (Ligand III has additional bands, including one at 1692 cm -1 of relatively weaker intensity it is difficult to identify the other bands. Complex formation and conjugation modify their locations. This could be the reason for the nature and position of bands in the chelates, specially those corresponding to ligand-bands at 1539 cm -1, 1553 cm -x and 1558 cm -x (probable Amide II), at 1519 cm -1, 1525 cm -1 and 1540 cm -1 (probable "NCS"), at 1490 cm - t (probable b(NH) and v(CN)), at 1250 ~ 1300 cm -1 (probable Amide III), at 1215 cm -x ~ 1 2 2 5 cm -x (probable ~(CN), b(NH)) and at ~ 7 5 0 cm -1 (probable v(CS) and v(CN)). The bands at 820 , ~ 845 cm -x for the chelates may also correspond to N---C--O and C - - S vibrations. However, these may be best explained if co-ordination by two azine nitrogen atoms and hydrogen bonding of NH/NH2 to C m O / C - - S . * Molecular models were tried. c16~K. Sw~mAx~.~ and H. M. N. H. IRVING,J. inorg, nucL Chem. 26, 1291 (1964). exT~E. R. BLowr, M. F ~ s and R. KARVLUS,J. Am. chem. Soc. 70, 195 (1948).

1644

A. DtrrrA Arn~D and P. K. M.ANDAL

A representation set of u.v. spectra of the metal chelates is shown in Fig. 3 (cf. Table 4). The spectra closely resemble the general character of those of the respective ligands at higher pH (el. Table 4 and Fig. 4). The significant feature is the general shift of the high energy band to a lower one and of the other to a higher energy. This may be due to more effective delocalization of electrons and increased metal ligand interaction. This should also corroborate the assignment of the ~ 2 0 5 mp band to N--~N--N=C--N skeleton. The following structure is proposed for the 1 : 1 complexes:

I c

N

N

o S

I

/

tt

s

I

N~

j

I

N~ C

C N

N

I

The magnetic susceptibility measurements show the nickel complexes to be paramagnetic; but the values are low for two unpaired electrons and the value for the Ni-ligand II is abnormally low. This might be due to metal-metal bonding. Only one copper complex could be obtained, Cu(Ligand III)2C1. JENSm,I and MIQUEL(1) could prepare only an inner metallic complex of nickel with N-thiobenzoyl N'-carbamoyl hydrazine. The magnetic data show the copper to be monovalent. The compound is unstable in water solution, becomes turbid and then violet with time, probably due to oxidation of the monovalent copper. The u.v. absorption spectrum was taken immediately after preparing the solution. It is similar to that of the ligand in water. The i.r. spectrum of this compound shows evidence of nitrogen co-ordination; but the NH2 group might be free. The magnitude of the shift in the carbonyl frequency is also not in favour of NH2 co-ordination. The stretching modes of C--~S are considered to be present. The following structure is proposed for this complex. S o --

I!

![

CsHs--N~N~--N~/~H--C--N

-q

/cu\ /c NH2--C--NH--NH--C--NH--CaH5 [ --

II

O

II

S

__l

Attempts to prepare the corresponding nitrates and sulphates failed. Acknowledgements--Authors' sincerest thanks are due to S~ P. S. KOLrUffKAR o f Regional Research Laboratory, Hyderabad, India for i.r. spectra, to Dr. P. BANDYOPADrrVAVof University College of Science,Universityof Calcutta for magneticmeasurementsand to Prof. N. K. Dtrrr for his stimulating interest and encouragement.