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Mixed ligand complexes of copper(I)—IV Interaction of tris(thiourea) copper(I) iodide with o-phenanthroline
Notes J. inorg, nucl. Chem.. 1972, Vol. 34, pp. 3591-3593.
Pergamon Press.
3591 Printed in Great Britain
Mixed ligand complexes of copper(I)- IV Interaction of tris(thiourea) copper(I) iodide with o-phenanthroline (Received 4 June 1972) ThE MIXED ligand complexes of tris(thiourea) copper(I) chloride and iodides with pyridine and 2-2, dipyridyl have been reported[l-3]. This paper describes the preparation and properties of similar complexes of tris(thiourea) copper(I) iodide with o-phenanthroline. EXPERIMENTAL o-Phenanthroline(o-phen) and thiourea(tu) were analytical grade B.D.H. product. The complex, ICu(tu)3] I, was prepared as described earlier [1]. Spectrophotometric measurements were performed in the visible range with transistorized Bausch and Lomb spectronic-20. The magnetic susceptibility measurements were made at 30°C with a thermostatted Gouy magnetic balance. Potentiometric measurements were carried out with Kaycee potentiometer, type MG3. Platinum and saturated calomel were employed as indicator and reference electrodes, respectively. Titrations were carried out with several solutions of Cu(tu)31-o-phen and Cul-tu-o-phen with varying concentrations of the reagents. Standard 1 x 10-1M nitric acid solution was used as titrant. A constant ionic strength was maintained in the solution by the addition of unimotar potassium chloride. The results of the potentiometric titrations are summarized in Table 1. The i.r. spectra of the complexes were taken with a Perkin-Elmer 230 recording spectrometer in the region 6-15 ~ employing standard KBr technique. Table 1.
S. no. conc. of the species 10 ml Cu(tu):d(l × 10-1 M) + 20 ml o-phen( 1 x 10-1 M) 2. 10 mlCu(tu).d(l x 10-' M) + 3 0 mlo-phen(1 x 10 ~M) 3. 10mlCu(tu)3I(l x 10-~M) + 40 ml o-phen(l x 10-1 M) 4. 10mlCul(l x 10-1M)+20ml o-phen(1 × 10-j M) 5. 10 ml C u l ( l × 10-~ M) + 30 ml o-phen(l x 10-7 M ) + 4 0 ml tu(1 x 10 ~M) 6. 10mlCul(1 x 10-~M)+40ml tu + 4 0 ml o-phen(l × 10-1 M)
Titrant value (ml of 0-1 M HNO:3
h
Complex formed
11.0
1
18 and 27
2
[Cu(tu):~o-phen] 1 or [Cu(tu)2 o-phen] 1 + tu [Cu(tu) o-phen2]l or ICu(o-phen)2]l + tu and [Cu(tu)2 o-phen] 1 [Cu(tu)o-phen2]l or [Cu(o-phen)2]l [Cu(o-phen).,] I and [Cu(o-phen)[l [Cu(tu)o-phen2]l or [Cu(o-phen)2]l and [Cu(tu).~ o-phen]l ICu(tu)2 o-phen]l [Cu(tu)2 o-phen] i
1 20
2
10and22
2
20 and 27.8
2
1 18and32
2
is the number of ligands attached to one central group. 1. A. U. Malik, Z. anorg, allgem. Chem. 363, 203 (1968). 2. M. M. Khan, A. U. Malik and S. A. A. Zaidi, J. electroanal. Chem., 25, 512 (1970). 3. M. M. Khan and A. U. Malik, J. electroanal. Chem. 29, 421 (1971).
3592
Notes
Preparation of the complexes About 2g of o-phen was added to 200 ml solution of 2% tris(tu) copper(I) iodide in acetone. The resulting red solution was concentrated and then allowed to stand for about half an hour. Black crystals appeared which settled to the bottom. The supernatant liquid was separated and on standing orange crystals deposited. The residual liquid was concentrated and pink needle shaped crystals were obtained after about 3 hr. (a) Bis(o-phen)copper(l) iodide, [Cu(o-phen)2]I Black fine crystals, m.p. 320°(2, soluble in ethanol and acetone, but insoluble in water. Calc. for C24H~sN4CuI: C, 53.3; H, 2.9; N, 10.2; Cu, 11.5; I, 23,05. Found: C, 52-1; H, 3.2; N, 10.3; Cu, 11.3; I, 23.2. (b) Bis(tu)mono(o-phen)copper(1) iodide, [Cu(tu)2o-phen]I Orange crystals, m.p. 230°(2, soluble in ethanol and highly soluble in acetone and insoluble in water Calc. for C~4H~6NsS~CuI: C, 32-15; H, 3-1; N, 16.1; S, 12-25; Cu, 12"15; I, 24"3. Found: C, 33.2; H, 3.8; N, 16"1; S, 12"2; Cu, 12.1; I, 24-1. (c) Bis(o-phen) mono(tu)copper(l) iodide, [Cu(tu)o-phen2]1 Needle shaped pink crystals, m.p. 195°C, soluble in water, acetone, and alcohol. Calc. for C25H20N6S CuI: C, 47.0; H, 3.2; N, 13"3; Cu, 10.1; I, 20-25; S, 5.1. Found: C, 46.3; H, 3.5; N, 13.2; Cu, 10'0; I, 20"1; S, 5"2. RESULTS AND DISCUSSION By the interaction of tris(tu) copper(I) iodide and o-phen, the following adducts were obtained: [Cu(tu)20-phen] I (orange), [Cu(tu)o-pben2] I (pink) and [Cu(o-phen)2]I (black). All the complexes were diamagnetic. The reaction between tris(tu) copper(I) iodide and o-phen is interesting in that there is evidence for the formation of penta-coordinate, [Cu(tu)o-phen2]I, and tetra coordinate, [Cu(tu)20-phen]I and [Cu(o-phen)2] I, species. The mechanism of the reaction may follow the path: Cu(tu)3I I
÷o-phe,) [Cu(tu)~o-phen]I II
+o-phe,) [Cu(tu)o-phen~]I ~ [Cu(o-phen)2]I+tu. III
IV
The formation of penta coordinate complexes of Cu(I) have also been reported previously [4)5] and therefore the formation of [Cu(tu)o-phen2] I, [II I] is not improbable in the present reaction. Using Job's method of continuous variation [6], the spectrophotometric studies on the interaction of Cu(tu)3I with o-phen indicate the combination of two ligand molecules with one central group. The formation of I : 2 complex supports the results of the potentiometric method. The i.r. spectra of the mixed ligand complexes were compared with the spectra of the heterocyclic amines and thiourea complexes of copper(I). Although it is difficult to assign particular bands specifically either to coordinate thiourea or coordinated amine, however, the spectra are marked by two distinct changes (i) the bands assigned to NH2 bending (ca. 1600 cm-1), N H deformation and CN antisymmetric stretching (ca. 1475 cm-~), and N - C - N stretching (ca. 1085 cm -~) remain almost unaltered on coordination, (ii) the bands in coordinated amine due to CC and CN stretching vibrations are greatly reduced in number. The strong band at 1600 cm -~ assigned to NH2 bending modes of thiourea is absent in [Cu(o-phen)2]I. The spectra in the region 600-800 cm -~ are marked by a number of bands which are assigned to CH out of plane hydrogen deformation vibrations of o-phen, and CS stretching modes of thiourea (730 cm -~ in tu). The strong band appearing at 710 cm -~ in the complexes corresponds to the CS stretching of thiourea, which lowers on coordination through sulphur, this band is absent in the complex, [Cu(o-phen)2]I. The presence of numerous bands in the spectra in this region may be due to the splitting of CH out of plane hydrogen deformation vibration hands. The latter occur 4. C. M. Harris, T. N. Lockyer, H. Waterman, G. A. Barclay and C. H. L. Kennard, Nature 192, 424 (1961). 5. C. M. Harris and E. D. McKenzie, J. inorg, nucl. Chem. 19, 372 (1961 ). 6. P. Job, Compt. Rend. 180, 928 (1925).
Notes
3593
due to coordination with heterocyclic nitrogen and the strong polarisation effect in the coordinated sphere by the large iodine atom [ 1]. The i.r. studies thus indicate the presence of coordinated thiourea and coordinated o-phen, in the mixed ligand complexes.
Department of Chem&try A ligarh Muslim University A ligarh U.P,, India
M. M. K H A N
A. U. M A L I K
J. inorg, nucl. Chem., 1972, Vol. 34, pp. 3593-3595.
Pergamon Press.
Printed in Great Britain
Amine-exchange reactions of (N-alkylisonitrosoacetylacetoneimino)(isonitrosoacetylacetoneimino)Ni(II) (Received 15 January 1972) THE AMINE-EXCHANGE (transimination) reactions of coordinated imine ligands have been investigated by several workers [1-7]. The reaction is of interest because of its preparative significance [6, 8] and because of its relation to the biological processes of transamination and deamination [5, 9]. Although several investigations on amine-exchange reactions are available, the factors affecting these reactions are still not clear. The influence of basicity and concentration [4, 6] have been variously discussed although pertinent experimental data arc not yet available. In this report, the observation of reversible amine-exchange reactions of coordinated imine-ligands in (N-alkylisonitrosoacetylacetoneimino)(isonitrosoacetylacetoneimino)Ni(II) are reported and the factors affecting these reactions are discussed on the basis of the experimental data. The structures of (N-alkylisonitrosoacetylacetoneimino)(isonitrosoacetylacetoneimino)Ni(I I) and bis(isonitrosoacctylacetoneimino)Ni(I I) have recently been suggested to be (I) and (II), respectively [8, 10]. ,~
H CH &/
0
,~
~
O
H
I
C
I/H~
o
8 3 c - / ~ ~O:N' \CH3 R
(|) Ni(R-IAI)(IAI') R = an alkyl group
H (II) Ni(IAI)(IAI')
L. F. Lindoy, Q. Rev. 25, 379 (1971). Y. Muto, Nippon. Kagaku Zasshi. 76, 252 (1960). Y. Muto, Ball. chem. Soc. Japan 33, 1242 (1960). H. S. Verter and A. E. Frost, J. Am. chem. Soc. 82, 85 (1960). D. F. Martin, Adv. chem. S er. 37, 192 (1963). E.J. Olszewski and D. F. Martin, J. inorg, nucl. Chem. 27, 345 (1965). E.J. Olszewski and D. F. Martin, J. inorg, nucl. Chem. 26, 1577 (! 964). K. S. Bose, B. C. Sharma and C. C. Patel, lnorg. Chem. In press. G. H. Eichhorn, The Chemistry of Coordination Compounds, (Edited by J. C. Bailar, Jr.), Chap. 21. Reinhold, New York (1956). I 0. M.J. Lacey, C. G. Macdonald, J. S. Shannon and P. J. Collins, A ust. J. Chem. 23, 2279 (1970). 1. 2. 3. 4. 5. 6. 7. 8. 9.
Pergamon Press.
3591 Printed in Great Britain
Mixed ligand complexes of copper(I)- IV Interaction of tris(thiourea) copper(I) iodide with o-phenanthroline (Received 4 June 1972) ThE MIXED ligand complexes of tris(thiourea) copper(I) chloride and iodides with pyridine and 2-2, dipyridyl have been reported[l-3]. This paper describes the preparation and properties of similar complexes of tris(thiourea) copper(I) iodide with o-phenanthroline. EXPERIMENTAL o-Phenanthroline(o-phen) and thiourea(tu) were analytical grade B.D.H. product. The complex, ICu(tu)3] I, was prepared as described earlier [1]. Spectrophotometric measurements were performed in the visible range with transistorized Bausch and Lomb spectronic-20. The magnetic susceptibility measurements were made at 30°C with a thermostatted Gouy magnetic balance. Potentiometric measurements were carried out with Kaycee potentiometer, type MG3. Platinum and saturated calomel were employed as indicator and reference electrodes, respectively. Titrations were carried out with several solutions of Cu(tu)31-o-phen and Cul-tu-o-phen with varying concentrations of the reagents. Standard 1 x 10-1M nitric acid solution was used as titrant. A constant ionic strength was maintained in the solution by the addition of unimotar potassium chloride. The results of the potentiometric titrations are summarized in Table 1. The i.r. spectra of the complexes were taken with a Perkin-Elmer 230 recording spectrometer in the region 6-15 ~ employing standard KBr technique. Table 1.
S. no. conc. of the species 10 ml Cu(tu):d(l × 10-1 M) + 20 ml o-phen( 1 x 10-1 M) 2. 10 mlCu(tu).d(l x 10-' M) + 3 0 mlo-phen(1 x 10 ~M) 3. 10mlCu(tu)3I(l x 10-~M) + 40 ml o-phen(l x 10-1 M) 4. 10mlCul(l x 10-1M)+20ml o-phen(1 × 10-j M) 5. 10 ml C u l ( l × 10-~ M) + 30 ml o-phen(l x 10-7 M ) + 4 0 ml tu(1 x 10 ~M) 6. 10mlCul(1 x 10-~M)+40ml tu + 4 0 ml o-phen(l × 10-1 M)
Titrant value (ml of 0-1 M HNO:3
h
Complex formed
11.0
1
18 and 27
2
[Cu(tu):~o-phen] 1 or [Cu(tu)2 o-phen] 1 + tu [Cu(tu) o-phen2]l or ICu(o-phen)2]l + tu and [Cu(tu)2 o-phen] 1 [Cu(tu)o-phen2]l or [Cu(o-phen)2]l [Cu(o-phen).,] I and [Cu(o-phen)[l [Cu(tu)o-phen2]l or [Cu(o-phen)2]l and [Cu(tu).~ o-phen]l ICu(tu)2 o-phen]l [Cu(tu)2 o-phen] i
1 20
2
10and22
2
20 and 27.8
2
1 18and32
2
is the number of ligands attached to one central group. 1. A. U. Malik, Z. anorg, allgem. Chem. 363, 203 (1968). 2. M. M. Khan, A. U. Malik and S. A. A. Zaidi, J. electroanal. Chem., 25, 512 (1970). 3. M. M. Khan and A. U. Malik, J. electroanal. Chem. 29, 421 (1971).
3592
Notes
Preparation of the complexes About 2g of o-phen was added to 200 ml solution of 2% tris(tu) copper(I) iodide in acetone. The resulting red solution was concentrated and then allowed to stand for about half an hour. Black crystals appeared which settled to the bottom. The supernatant liquid was separated and on standing orange crystals deposited. The residual liquid was concentrated and pink needle shaped crystals were obtained after about 3 hr. (a) Bis(o-phen)copper(l) iodide, [Cu(o-phen)2]I Black fine crystals, m.p. 320°(2, soluble in ethanol and acetone, but insoluble in water. Calc. for C24H~sN4CuI: C, 53.3; H, 2.9; N, 10.2; Cu, 11.5; I, 23,05. Found: C, 52-1; H, 3.2; N, 10.3; Cu, 11.3; I, 23.2. (b) Bis(tu)mono(o-phen)copper(1) iodide, [Cu(tu)2o-phen]I Orange crystals, m.p. 230°(2, soluble in ethanol and highly soluble in acetone and insoluble in water Calc. for C~4H~6NsS~CuI: C, 32-15; H, 3-1; N, 16.1; S, 12-25; Cu, 12"15; I, 24"3. Found: C, 33.2; H, 3.8; N, 16"1; S, 12"2; Cu, 12.1; I, 24-1. (c) Bis(o-phen) mono(tu)copper(l) iodide, [Cu(tu)o-phen2]1 Needle shaped pink crystals, m.p. 195°C, soluble in water, acetone, and alcohol. Calc. for C25H20N6S CuI: C, 47.0; H, 3.2; N, 13"3; Cu, 10.1; I, 20-25; S, 5.1. Found: C, 46.3; H, 3.5; N, 13.2; Cu, 10'0; I, 20"1; S, 5"2. RESULTS AND DISCUSSION By the interaction of tris(tu) copper(I) iodide and o-phen, the following adducts were obtained: [Cu(tu)20-phen] I (orange), [Cu(tu)o-pben2] I (pink) and [Cu(o-phen)2]I (black). All the complexes were diamagnetic. The reaction between tris(tu) copper(I) iodide and o-phen is interesting in that there is evidence for the formation of penta-coordinate, [Cu(tu)o-phen2]I, and tetra coordinate, [Cu(tu)20-phen]I and [Cu(o-phen)2] I, species. The mechanism of the reaction may follow the path: Cu(tu)3I I
÷o-phe,) [Cu(tu)~o-phen]I II
+o-phe,) [Cu(tu)o-phen~]I ~ [Cu(o-phen)2]I+tu. III
IV
The formation of penta coordinate complexes of Cu(I) have also been reported previously [4)5] and therefore the formation of [Cu(tu)o-phen2] I, [II I] is not improbable in the present reaction. Using Job's method of continuous variation [6], the spectrophotometric studies on the interaction of Cu(tu)3I with o-phen indicate the combination of two ligand molecules with one central group. The formation of I : 2 complex supports the results of the potentiometric method. The i.r. spectra of the mixed ligand complexes were compared with the spectra of the heterocyclic amines and thiourea complexes of copper(I). Although it is difficult to assign particular bands specifically either to coordinate thiourea or coordinated amine, however, the spectra are marked by two distinct changes (i) the bands assigned to NH2 bending (ca. 1600 cm-1), N H deformation and CN antisymmetric stretching (ca. 1475 cm-~), and N - C - N stretching (ca. 1085 cm -~) remain almost unaltered on coordination, (ii) the bands in coordinated amine due to CC and CN stretching vibrations are greatly reduced in number. The strong band at 1600 cm -~ assigned to NH2 bending modes of thiourea is absent in [Cu(o-phen)2]I. The spectra in the region 600-800 cm -~ are marked by a number of bands which are assigned to CH out of plane hydrogen deformation vibrations of o-phen, and CS stretching modes of thiourea (730 cm -~ in tu). The strong band appearing at 710 cm -~ in the complexes corresponds to the CS stretching of thiourea, which lowers on coordination through sulphur, this band is absent in the complex, [Cu(o-phen)2]I. The presence of numerous bands in the spectra in this region may be due to the splitting of CH out of plane hydrogen deformation vibration hands. The latter occur 4. C. M. Harris, T. N. Lockyer, H. Waterman, G. A. Barclay and C. H. L. Kennard, Nature 192, 424 (1961). 5. C. M. Harris and E. D. McKenzie, J. inorg, nucl. Chem. 19, 372 (1961 ). 6. P. Job, Compt. Rend. 180, 928 (1925).
Notes
3593
due to coordination with heterocyclic nitrogen and the strong polarisation effect in the coordinated sphere by the large iodine atom [ 1]. The i.r. studies thus indicate the presence of coordinated thiourea and coordinated o-phen, in the mixed ligand complexes.
Department of Chem&try A ligarh Muslim University A ligarh U.P,, India
M. M. K H A N
A. U. M A L I K
J. inorg, nucl. Chem., 1972, Vol. 34, pp. 3593-3595.
Pergamon Press.
Printed in Great Britain
Amine-exchange reactions of (N-alkylisonitrosoacetylacetoneimino)(isonitrosoacetylacetoneimino)Ni(II) (Received 15 January 1972) THE AMINE-EXCHANGE (transimination) reactions of coordinated imine ligands have been investigated by several workers [1-7]. The reaction is of interest because of its preparative significance [6, 8] and because of its relation to the biological processes of transamination and deamination [5, 9]. Although several investigations on amine-exchange reactions are available, the factors affecting these reactions are still not clear. The influence of basicity and concentration [4, 6] have been variously discussed although pertinent experimental data arc not yet available. In this report, the observation of reversible amine-exchange reactions of coordinated imine-ligands in (N-alkylisonitrosoacetylacetoneimino)(isonitrosoacetylacetoneimino)Ni(II) are reported and the factors affecting these reactions are discussed on the basis of the experimental data. The structures of (N-alkylisonitrosoacetylacetoneimino)(isonitrosoacetylacetoneimino)Ni(I I) and bis(isonitrosoacctylacetoneimino)Ni(I I) have recently been suggested to be (I) and (II), respectively [8, 10]. ,~
H CH &/
0
,~
~
O
H
I
C
I/H~
o
8 3 c - / ~ ~O:N' \CH3 R
(|) Ni(R-IAI)(IAI') R = an alkyl group
H (II) Ni(IAI)(IAI')
L. F. Lindoy, Q. Rev. 25, 379 (1971). Y. Muto, Nippon. Kagaku Zasshi. 76, 252 (1960). Y. Muto, Ball. chem. Soc. Japan 33, 1242 (1960). H. S. Verter and A. E. Frost, J. Am. chem. Soc. 82, 85 (1960). D. F. Martin, Adv. chem. S er. 37, 192 (1963). E.J. Olszewski and D. F. Martin, J. inorg, nucl. Chem. 27, 345 (1965). E.J. Olszewski and D. F. Martin, J. inorg, nucl. Chem. 26, 1577 (! 964). K. S. Bose, B. C. Sharma and C. C. Patel, lnorg. Chem. In press. G. H. Eichhorn, The Chemistry of Coordination Compounds, (Edited by J. C. Bailar, Jr.), Chap. 21. Reinhold, New York (1956). I 0. M.J. Lacey, C. G. Macdonald, J. S. Shannon and P. J. Collins, A ust. J. Chem. 23, 2279 (1970). 1. 2. 3. 4. 5. 6. 7. 8. 9.