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IR, PMR and Mössbauer studies on the complexes of triphenyltin chloride and triphenyltin isothiocyanate with a series of N-alkylsalicylideneimines
IR, PMR AND MbSBAUER STUDIES ON THE COMPLEXES OF TRIPHENYLTIN CHLORIDE AND TRIPHENYLTIN ISOTHIOCYANATE WITH A SERIES OF N-ALKYLSALICYLIDENEIMINES LIAN E. KHOO School of Chemical Sciences, Universiti Sains Malaysia, Penang, Malaysia
FRANK E. SMITH* Chemistry Department, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Received 13 July 1984; accepted 21 August 1984) Abstract-Eleven new complexes of the type Ph,SnX: o-HOCsH4CH=NR (X = Cl, NCS; R = CH,, t-Bu, PhCH2, ~J-C~H~~,c-C~H~~, HOCH,CH,) have been synthesized by the reactions of triphenyltin chloride or isothiocyanate with the N-alkylsalicylideneimines. The complexes are non-electrolytes in nitrobenzene. IR, PMR and Miissbauer spectroscopic studies indicate that the ligands are behaving as monodentates via the phenolic oxygen atoms, and that the complexes all have trigonal bipyramidal geometry with the phenyl groups occupying the equatorial positions.
Several reports concerning the S&%-base complexes of mono- and diorganotin compounds have appeared recently.1-6 We now wish to report the results of our investigations on the S&i&base complexes of triorganotin compounds. We have synthesised and characterised a series of new complexes between Ph3SnX (X = Cl, NCS) and the Schiff bases
the water formed being removed azeotropically. The Schilf bases were purified by fractional distillation. The complexes were prepared by refluxing the calculated amounts of ligand and triphenyltin chloride or isothiocyanate in 95% ethanol for l-2 h. The complexes crystallised out when the solutions were cooled in a refrigerator overnight. They were filtered off and recrystallised from ethanol. Melting points for the complexes are given in Table 1. ’ Conductance measurements in nitrobenzene were pN,R made at room temperature using a Phillips PW 9501 I H conductivity bridgewithacellconstantof0.71 cm-‘. Molar conductances of the complexes are recorded where R = CHJ, t-Bu, PhCH2, n-C6H13, c-C6H,,, in Table 1. OHCH&H,. The IR spectra of the ligands and complexes were EXPERIMENTAL recorded in the region w cm-’ with a Triphenyltin chloride was purchased from Alfa Beckmann Acculab ‘4’ instrument either as neat liquid film or Nujol mulls between NaCl plates. For Inorganics and used without further purification. Triphenyltin isothiocyanate (m.p. 168-170°C) was the 600-200 cm-’ region, the Beckmann IR4250 spectrophotometer was used and the spectra were prepared from triphenyltin chloride and potassium recorded as neat liquid or Nujol mulls, CsI discs, or thiocyanate by the literature method,’ and between polythene plates. recrystallised from benzene before use. PMR spectra were obtained with a Varian CFTThe N-alkylsalicylideneimines were synthesised 20 spectrometer with deuterochloroform as solvent. by the condensation of salicylaldehyde with the Miissbauer spectra were recorded at the appropriate primary amine in refluxing benzene, International Tin Research Institute, Greenford, * Author to whom correspondence should be addressed. England.
:
:I a
O.H
447
L. E.
448
KHOO and F. E. SMITH
Table 1. Analytical, melting point and conductivity data for the complexes Complex Ph,SnX : o-HOC,H,CH=NR X
R
Cl NCS Cl NCS Cl NCS Cl NCS Cl NCS Cl
CH, CH, t-Bu t-Bu PhCHz PhCH, HOCH,CH, HOCH,CH, c-C,H,, c-GHI I n-C,H,,
Elemental analysis (%) Found (talc.) H
C 60.00 59.98 61.70 61.03 64.04 64.40 58.10 58.42 62.95 62.61 62.74
(59.98) (59.68) (61.87) (61.55) (64.40) (63.99) (58.89) (58.65) (63.02) (62.86) (63.02)
4.79 4.61 5.55 5.23 4.85 4.78 4.78 4.78 5.79 5.48 6.13
(4.66) (4.46) (5.38) (5.18) (4.75) (4.57) (4.77) (4.58) (5.49) (5.29) (5.81)
Tin was estimated as SnO,. Microanalyses were carried out by the Chemistry Department, National University of Singapore, Singapore.
N 2.68 5.10 2.49 5.06 2.33 4.93 2.81 4.89 2.14 4.64 2.37
Sn
(2.69) (5.16) (2.49) (4.79) (2.35) (4.52) (2.55) (4.89) (2.38) (4.58) (2.37)
23.15 22.89 21.63 20.28 20.54 19.34 21.91 21.45 20.21 17.23 19.69
Complex Ph,SnX: o-HOC!,H,CH=NR R
AND DISCUSSION
Regardless of the proportions of ligand and triphenyltin compound used, the complexes all crystallised with 1: 1 stoichiometry. They were all yellow in colour, thermally stable with sharplydefined melting points and were found to be soluble in the common organic solvents. Microanalytical and conductance data for the complexes are presented in Table 1. The observed molar conductances in nitrobenzene were in the range 1.43.0 ohm-’ cm2 mol-‘, indicating that the compounds were non-electrolytes and that in each instance, the chloride or isothiocyanate group is bound to the tin atom. (Molar conductances expected for 1: 1 and 1: 2 electrolytes in nitrobenzene are 25-35 and 44-60 ohm-’ cm2 mol-‘, respectively.* Some data from the PMR spectra of the complexes are listed in Table 2. Comparison of the integrated intensities of the ligand and organotin protons confirms the 1: 1 stoichiometry of the complexes. The sharp singlet assigned to the azomethine proton9 of the ligands (6 N 8.2 ppm) was found to be unchanged on coordination, indicating that the Natom is not coordinated to the metal. On the other hand, the peak due to the phenolic proton for each ligand molecule (6 N 13 ppm) was significantly broadened on complex formation. As the ring formed by the intramolecular hydrogen bond of the Schi&base ligand is retained, but distorted in the complexes,‘* 3 coordination through oxygen will
mol- ‘)
106-108 136-138 136-138 177-180 110-111 160-161 111-112 128-130 130-132 173-175 66-67
1.60 2.29 1.51 3.02 1.51 2.13 1.51 2.66 1.42 2.57 1.42
Table 2. PMR data for the complexes
X
RESULTS
(22.80) (21.85) (21.08) (20.51) (19.89) (19.16) (21.55) (20.70) (20.16) (19.41) (20.09)
m.p. (“C)
Molar conductance (ohms-’ cm2
Cl NCS Cl NCS Cl NCS Cl NCS Cl NCS Cl
CH, CH, PhCHz PhCH, t-Bu t-Bu c-‘AHI I c-&H, I HOCH&H, HOCHJH, n-‘AH,,
Azomethine proton CH=NR
Phenolic OH6
(Ppm)
(ppm)
8.17 8.10 8.23 8.28 8.25 8.13 8.27 8.25 8.28 8.10 8.24
13.20 13.10 13.18 13.18 13.08 13.00 13.0 12.9 * * 13.05
* Not detected.
result in a weakening of the O-H b.ond, and a strengthening of the C=N---H hydrogen bond, which in turn leads to the observed broadening of the peak due to the phenolic proton. Similar observations have been reported for the dialkyltin chloride complexes of N-arylsalicylideneimines,4 and of N,N’-bis(salicylaldehyde) ethylenediimine.” The IR evidence (Table 3) also suggests that the ligands are behaving as monodentates via the oxygen atoms. A strong band assigned to the C-N stretching vibrationg-” is observed at 1633-1645 - 1for the ligands. However, in the complexes, this End shifts slightly towards higher frequency (1645 1660 cm - ‘). Similar shifts in C=N stretching frequency for ligands of this type have been found to indicate coordination to the tin atom by oxygen.‘-5* lo This has been confirmed by the X-ray
Studies on the compkxes of triphenyltin chloride and triphenyltin isothiocyanate
449
Table 3. IR data for the complexes Complex Ph,SnX : o-HOC,H,CH=NR
v (Sn-Ph)
v (CV X
R
Cl NCS Cl NCS Cl NCS Cl NCS Cl NCS Cl
CHJ CH, t-Bu t-Bu PhCH, PhCHz HOCHzCHz HOCHICHz c-CsH, i c-&H, 1 n-&H,,
(m-l)
(cm-‘)
(cm-‘)
1660 1660 1653 1650 1650 1655 1645 1655 1645 1650 1655
275 275 280 275 270 275 275 275 270 275 275
230 230 230 230 225 235 220 230 225 230 220
v mm
v (Sn-Cl)
(Cm-9
(cm-9
2050 2060 2070
235 240
2060 2060
225 235 -
-
235
235 -
* v (CN) for ligand. t v (CN) for NCS group.
assigned to tin-phenyl stretching vibrations. The frequencies of these vibrations are largely unaffected by changes in the coordination number of the tin atom, and occur at almost the same frequencies as in the parent triphenyltin chloride and isothiocyanate.14 Each of the triphenyltin chloride complexes displayed a band in the region 225-240 cm-‘. These are assigned to the Sri-Cl stretching mode, which is sensitive to an increase in coordination round the tin atom, and in each case is shifted downfield by some 100 cm- ’ from its value in triphenyltin chloride. l4 The strong absorption observed at - 2060 cm-’ for all the isothiocyanate complexes suggests that the thiocyanate groups are N-bonded in each case.’ 5 The results so far discussed, including the analytical, PMR, conductivity and IR data, strongly support the assignment of a five-coordinate structure to the complexes. The three possible isomers for trigonal bipyramidal complexes of this type are shown in Fig. 1. It has been shown,16* l7 that each of these three possible isomers would be expected to show a different quadrupole splitting (AQvalue in the Mbsbauer spectrum. For isomers
structural analysis of the complex of dimethyltin dichloride with N,N-ethylenebis(salicylideneimine). l 2 Due to the strong intramolecular hydrogen bonding present, the stretching vibration of the phenolic O-H is lowered and broadenedi and the weak, broad bands observed in the spectra of the ligands in the 260@-3000 cm-’ range are attributed to these restricted vibrations. For the complexes, these bands are shifted towards higher energies by about 200 cm-‘, which is further evidence that the ring formed by the intramolecular hydrogen bond of the ligand although distorted, is still present after complex formation has occurred.” In the case of the ligand o-HOC6H4CH=NCH2CH20H, a band at 3350 cm-’ is assigned to the alcoholic O-H stretching absorption. This band does not change on complex formation, indicating that the free alcohol group present in this molecule plays no part in the coordination of the ligand to the metal. In the low frequency IR region, bands observed at - 220 and - 280 cm- ’ in all the complexes are
L
I I’
L
L--Stl /R R I
I I\
R
R-SnAR R
L II
I I\
R---Sn YL R
R III
Fig. 1. Possible isomers of trigonal bipyramidyl R,SnL,.
L
450
L. E. KHOO
and F. E. SMITH
Table 4. Miissbauer data for the complexes*
Complex o-HOC,H,CH=NCH, : Ph,SnCl o-HOC,H,CH=NCH, : PhsSnNCS o-HOCsH4CH=NCH2CH20H : Ph,SnCl o-HOC,H,CH=NCH,CH,OH : PhsSnNCS
Isomer shift-f 6(mms-I)
Quadrupole splitting (A&) (mm s-l)
1.24 1.20 1.26 1.21
3.10 3.22 3.23 3.42
* The accuracy for all these parameters is k 0.05 mm s-r. t Relative to BaSnO,.
REFERENCES
H
crl=I Ph
1; P
/R
+ -.-.. S,,-Ph
Phd
1 X
Fig. 2. Proposed structures of the complexes.
1. B. S. Saraswat, G. Srivatava and R. C. Mehrotra, J. Organomet. Chem. 1979,164,153. 2. B. S. Saraswat, G. Srivastava, R. C:Mehrotra, G. Sawhney and J. S. Baijal, J. Znorg. Nucl. Chem. 1980, 42, 805. 3. B. S. Saraswat, G. Srivastava and R. C. Mehrotra, Inorg. Chim. Acta 1979,36,289. 4. L. E. Khoo and F. E. Smith, Polyhedron 1982,1,213. 5. T. N. Srivastava and A. K. S. Chuhan, J. Znorg. Nucl.
Chem. 1977,39,371.
oftypeI,therangeofAEois1.7-2.3mms-’,forII,33.9 mm s-r and for III, 3.5-4.1 mm s-l. The AE, values (Table 4) obtained for the complexes described herein fall in the range 3.10-3.42 mm s-r, and thus clearly belong to category II. We believe that the complexes of the Nalkylsalicylideneimines with triphenyltin chloride and isothiocyanate have five-coordinate, trigonal bipyramidal structures, with the phenyl groups occupying the equatorial positions and the ligands behaving as monodentates through the phenolic oxygen atoms, as shown in Fig. 2. The assignment of such structures is entirely consistent with the stereochemistry of other triorganotin complexes.‘s
6. T. N. Srivastava, A. K. S. Chuhan and M. Agarwal, J. Znorg. Nucl. Chem. 1979,41,896. 7. K. C. Panda., J. Organomet. Chem. 1968,13,187. 8. J. A. Walmsley and S. Y. Tyree, Znorg. Chem. 1963,2, 312. 9. G. C. Percy and D. A. Thornton, J. Znorg. Nucl. Chem.
1972,34,3369. 10. K. Kawakami, M. Miya-uchi and T. Tanaka, J. Znorg. Nucl. Chem. 1971,33,3773. 11. L. E. Clougherty, J. A. Sousa and G. M. Wyman, J. Org. Chem. 1957,22,462.
12. L. Randaccio, J. Organomet. Chem. 1973,55, C58. 13. H. H. Freedman, J. Am. Chem. Sot. 1961,83,2900. 14. R. C. Poller, The Chemistry of Organotin Compounds, p. 227. Logos Press (1970). 15. R. A. Bailey, S. L. Kozak, T. W. Michelsen and W. N. Mills, Coord. Chem. Rev. 1971,6,407. 16. G. M. Bancroft, V. G. Kumar Das and T. K. Sham, J. Chem. Sot., Chem. Commun. 1974,236.
Acknowledgements-We
thank Dr P. J. Smith for the Mossbauer spectra, Mr C. L. Yee for technical assistance and Universiti Sains Malaysia and NSERC (Canada) for financial support.
17. G. M. Bancroft, V. G. Kumar Das, T. K. Sham and M. G. Clark, J. Chem. Sot., Dalton Trans. 1976,643. 18. P. G. Harrison, K. Lambert, T. J. King and B. Majee, J. Chem. Sot., Dalton Trans. 1983,363.
FRANK E. SMITH* Chemistry Department, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Received 13 July 1984; accepted 21 August 1984) Abstract-Eleven new complexes of the type Ph,SnX: o-HOCsH4CH=NR (X = Cl, NCS; R = CH,, t-Bu, PhCH2, ~J-C~H~~,c-C~H~~, HOCH,CH,) have been synthesized by the reactions of triphenyltin chloride or isothiocyanate with the N-alkylsalicylideneimines. The complexes are non-electrolytes in nitrobenzene. IR, PMR and Miissbauer spectroscopic studies indicate that the ligands are behaving as monodentates via the phenolic oxygen atoms, and that the complexes all have trigonal bipyramidal geometry with the phenyl groups occupying the equatorial positions.
Several reports concerning the S&%-base complexes of mono- and diorganotin compounds have appeared recently.1-6 We now wish to report the results of our investigations on the S&i&base complexes of triorganotin compounds. We have synthesised and characterised a series of new complexes between Ph3SnX (X = Cl, NCS) and the Schiff bases
the water formed being removed azeotropically. The Schilf bases were purified by fractional distillation. The complexes were prepared by refluxing the calculated amounts of ligand and triphenyltin chloride or isothiocyanate in 95% ethanol for l-2 h. The complexes crystallised out when the solutions were cooled in a refrigerator overnight. They were filtered off and recrystallised from ethanol. Melting points for the complexes are given in Table 1. ’ Conductance measurements in nitrobenzene were pN,R made at room temperature using a Phillips PW 9501 I H conductivity bridgewithacellconstantof0.71 cm-‘. Molar conductances of the complexes are recorded where R = CHJ, t-Bu, PhCH2, n-C6H13, c-C6H,,, in Table 1. OHCH&H,. The IR spectra of the ligands and complexes were EXPERIMENTAL recorded in the region w cm-’ with a Triphenyltin chloride was purchased from Alfa Beckmann Acculab ‘4’ instrument either as neat liquid film or Nujol mulls between NaCl plates. For Inorganics and used without further purification. Triphenyltin isothiocyanate (m.p. 168-170°C) was the 600-200 cm-’ region, the Beckmann IR4250 spectrophotometer was used and the spectra were prepared from triphenyltin chloride and potassium recorded as neat liquid or Nujol mulls, CsI discs, or thiocyanate by the literature method,’ and between polythene plates. recrystallised from benzene before use. PMR spectra were obtained with a Varian CFTThe N-alkylsalicylideneimines were synthesised 20 spectrometer with deuterochloroform as solvent. by the condensation of salicylaldehyde with the Miissbauer spectra were recorded at the appropriate primary amine in refluxing benzene, International Tin Research Institute, Greenford, * Author to whom correspondence should be addressed. England.
:
:I a
O.H
447
L. E.
448
KHOO and F. E. SMITH
Table 1. Analytical, melting point and conductivity data for the complexes Complex Ph,SnX : o-HOC,H,CH=NR X
R
Cl NCS Cl NCS Cl NCS Cl NCS Cl NCS Cl
CH, CH, t-Bu t-Bu PhCHz PhCH, HOCH,CH, HOCH,CH, c-C,H,, c-GHI I n-C,H,,
Elemental analysis (%) Found (talc.) H
C 60.00 59.98 61.70 61.03 64.04 64.40 58.10 58.42 62.95 62.61 62.74
(59.98) (59.68) (61.87) (61.55) (64.40) (63.99) (58.89) (58.65) (63.02) (62.86) (63.02)
4.79 4.61 5.55 5.23 4.85 4.78 4.78 4.78 5.79 5.48 6.13
(4.66) (4.46) (5.38) (5.18) (4.75) (4.57) (4.77) (4.58) (5.49) (5.29) (5.81)
Tin was estimated as SnO,. Microanalyses were carried out by the Chemistry Department, National University of Singapore, Singapore.
N 2.68 5.10 2.49 5.06 2.33 4.93 2.81 4.89 2.14 4.64 2.37
Sn
(2.69) (5.16) (2.49) (4.79) (2.35) (4.52) (2.55) (4.89) (2.38) (4.58) (2.37)
23.15 22.89 21.63 20.28 20.54 19.34 21.91 21.45 20.21 17.23 19.69
Complex Ph,SnX: o-HOC!,H,CH=NR R
AND DISCUSSION
Regardless of the proportions of ligand and triphenyltin compound used, the complexes all crystallised with 1: 1 stoichiometry. They were all yellow in colour, thermally stable with sharplydefined melting points and were found to be soluble in the common organic solvents. Microanalytical and conductance data for the complexes are presented in Table 1. The observed molar conductances in nitrobenzene were in the range 1.43.0 ohm-’ cm2 mol-‘, indicating that the compounds were non-electrolytes and that in each instance, the chloride or isothiocyanate group is bound to the tin atom. (Molar conductances expected for 1: 1 and 1: 2 electrolytes in nitrobenzene are 25-35 and 44-60 ohm-’ cm2 mol-‘, respectively.* Some data from the PMR spectra of the complexes are listed in Table 2. Comparison of the integrated intensities of the ligand and organotin protons confirms the 1: 1 stoichiometry of the complexes. The sharp singlet assigned to the azomethine proton9 of the ligands (6 N 8.2 ppm) was found to be unchanged on coordination, indicating that the Natom is not coordinated to the metal. On the other hand, the peak due to the phenolic proton for each ligand molecule (6 N 13 ppm) was significantly broadened on complex formation. As the ring formed by the intramolecular hydrogen bond of the Schi&base ligand is retained, but distorted in the complexes,‘* 3 coordination through oxygen will
mol- ‘)
106-108 136-138 136-138 177-180 110-111 160-161 111-112 128-130 130-132 173-175 66-67
1.60 2.29 1.51 3.02 1.51 2.13 1.51 2.66 1.42 2.57 1.42
Table 2. PMR data for the complexes
X
RESULTS
(22.80) (21.85) (21.08) (20.51) (19.89) (19.16) (21.55) (20.70) (20.16) (19.41) (20.09)
m.p. (“C)
Molar conductance (ohms-’ cm2
Cl NCS Cl NCS Cl NCS Cl NCS Cl NCS Cl
CH, CH, PhCHz PhCH, t-Bu t-Bu c-‘AHI I c-&H, I HOCH&H, HOCHJH, n-‘AH,,
Azomethine proton CH=NR
Phenolic OH6
(Ppm)
(ppm)
8.17 8.10 8.23 8.28 8.25 8.13 8.27 8.25 8.28 8.10 8.24
13.20 13.10 13.18 13.18 13.08 13.00 13.0 12.9 * * 13.05
* Not detected.
result in a weakening of the O-H b.ond, and a strengthening of the C=N---H hydrogen bond, which in turn leads to the observed broadening of the peak due to the phenolic proton. Similar observations have been reported for the dialkyltin chloride complexes of N-arylsalicylideneimines,4 and of N,N’-bis(salicylaldehyde) ethylenediimine.” The IR evidence (Table 3) also suggests that the ligands are behaving as monodentates via the oxygen atoms. A strong band assigned to the C-N stretching vibrationg-” is observed at 1633-1645 - 1for the ligands. However, in the complexes, this End shifts slightly towards higher frequency (1645 1660 cm - ‘). Similar shifts in C=N stretching frequency for ligands of this type have been found to indicate coordination to the tin atom by oxygen.‘-5* lo This has been confirmed by the X-ray
Studies on the compkxes of triphenyltin chloride and triphenyltin isothiocyanate
449
Table 3. IR data for the complexes Complex Ph,SnX : o-HOC,H,CH=NR
v (Sn-Ph)
v (CV X
R
Cl NCS Cl NCS Cl NCS Cl NCS Cl NCS Cl
CHJ CH, t-Bu t-Bu PhCH, PhCHz HOCHzCHz HOCHICHz c-CsH, i c-&H, 1 n-&H,,
(m-l)
(cm-‘)
(cm-‘)
1660 1660 1653 1650 1650 1655 1645 1655 1645 1650 1655
275 275 280 275 270 275 275 275 270 275 275
230 230 230 230 225 235 220 230 225 230 220
v mm
v (Sn-Cl)
(Cm-9
(cm-9
2050 2060 2070
235 240
2060 2060
225 235 -
-
235
235 -
* v (CN) for ligand. t v (CN) for NCS group.
assigned to tin-phenyl stretching vibrations. The frequencies of these vibrations are largely unaffected by changes in the coordination number of the tin atom, and occur at almost the same frequencies as in the parent triphenyltin chloride and isothiocyanate.14 Each of the triphenyltin chloride complexes displayed a band in the region 225-240 cm-‘. These are assigned to the Sri-Cl stretching mode, which is sensitive to an increase in coordination round the tin atom, and in each case is shifted downfield by some 100 cm- ’ from its value in triphenyltin chloride. l4 The strong absorption observed at - 2060 cm-’ for all the isothiocyanate complexes suggests that the thiocyanate groups are N-bonded in each case.’ 5 The results so far discussed, including the analytical, PMR, conductivity and IR data, strongly support the assignment of a five-coordinate structure to the complexes. The three possible isomers for trigonal bipyramidal complexes of this type are shown in Fig. 1. It has been shown,16* l7 that each of these three possible isomers would be expected to show a different quadrupole splitting (AQvalue in the Mbsbauer spectrum. For isomers
structural analysis of the complex of dimethyltin dichloride with N,N-ethylenebis(salicylideneimine). l 2 Due to the strong intramolecular hydrogen bonding present, the stretching vibration of the phenolic O-H is lowered and broadenedi and the weak, broad bands observed in the spectra of the ligands in the 260@-3000 cm-’ range are attributed to these restricted vibrations. For the complexes, these bands are shifted towards higher energies by about 200 cm-‘, which is further evidence that the ring formed by the intramolecular hydrogen bond of the ligand although distorted, is still present after complex formation has occurred.” In the case of the ligand o-HOC6H4CH=NCH2CH20H, a band at 3350 cm-’ is assigned to the alcoholic O-H stretching absorption. This band does not change on complex formation, indicating that the free alcohol group present in this molecule plays no part in the coordination of the ligand to the metal. In the low frequency IR region, bands observed at - 220 and - 280 cm- ’ in all the complexes are
L
I I’
L
L--Stl /R R I
I I\
R
R-SnAR R
L II
I I\
R---Sn YL R
R III
Fig. 1. Possible isomers of trigonal bipyramidyl R,SnL,.
L
450
L. E. KHOO
and F. E. SMITH
Table 4. Miissbauer data for the complexes*
Complex o-HOC,H,CH=NCH, : Ph,SnCl o-HOC,H,CH=NCH, : PhsSnNCS o-HOCsH4CH=NCH2CH20H : Ph,SnCl o-HOC,H,CH=NCH,CH,OH : PhsSnNCS
Isomer shift-f 6(mms-I)
Quadrupole splitting (A&) (mm s-l)
1.24 1.20 1.26 1.21
3.10 3.22 3.23 3.42
* The accuracy for all these parameters is k 0.05 mm s-r. t Relative to BaSnO,.
REFERENCES
H
crl=I Ph
1; P
/R
+ -.-.. S,,-Ph
Phd
1 X
Fig. 2. Proposed structures of the complexes.
1. B. S. Saraswat, G. Srivatava and R. C. Mehrotra, J. Organomet. Chem. 1979,164,153. 2. B. S. Saraswat, G. Srivastava, R. C:Mehrotra, G. Sawhney and J. S. Baijal, J. Znorg. Nucl. Chem. 1980, 42, 805. 3. B. S. Saraswat, G. Srivastava and R. C. Mehrotra, Inorg. Chim. Acta 1979,36,289. 4. L. E. Khoo and F. E. Smith, Polyhedron 1982,1,213. 5. T. N. Srivastava and A. K. S. Chuhan, J. Znorg. Nucl.
Chem. 1977,39,371.
oftypeI,therangeofAEois1.7-2.3mms-’,forII,33.9 mm s-r and for III, 3.5-4.1 mm s-l. The AE, values (Table 4) obtained for the complexes described herein fall in the range 3.10-3.42 mm s-r, and thus clearly belong to category II. We believe that the complexes of the Nalkylsalicylideneimines with triphenyltin chloride and isothiocyanate have five-coordinate, trigonal bipyramidal structures, with the phenyl groups occupying the equatorial positions and the ligands behaving as monodentates through the phenolic oxygen atoms, as shown in Fig. 2. The assignment of such structures is entirely consistent with the stereochemistry of other triorganotin complexes.‘s
6. T. N. Srivastava, A. K. S. Chuhan and M. Agarwal, J. Znorg. Nucl. Chem. 1979,41,896. 7. K. C. Panda., J. Organomet. Chem. 1968,13,187. 8. J. A. Walmsley and S. Y. Tyree, Znorg. Chem. 1963,2, 312. 9. G. C. Percy and D. A. Thornton, J. Znorg. Nucl. Chem.
1972,34,3369. 10. K. Kawakami, M. Miya-uchi and T. Tanaka, J. Znorg. Nucl. Chem. 1971,33,3773. 11. L. E. Clougherty, J. A. Sousa and G. M. Wyman, J. Org. Chem. 1957,22,462.
12. L. Randaccio, J. Organomet. Chem. 1973,55, C58. 13. H. H. Freedman, J. Am. Chem. Sot. 1961,83,2900. 14. R. C. Poller, The Chemistry of Organotin Compounds, p. 227. Logos Press (1970). 15. R. A. Bailey, S. L. Kozak, T. W. Michelsen and W. N. Mills, Coord. Chem. Rev. 1971,6,407. 16. G. M. Bancroft, V. G. Kumar Das and T. K. Sham, J. Chem. Sot., Chem. Commun. 1974,236.
Acknowledgements-We
thank Dr P. J. Smith for the Mossbauer spectra, Mr C. L. Yee for technical assistance and Universiti Sains Malaysia and NSERC (Canada) for financial support.
17. G. M. Bancroft, V. G. Kumar Das, T. K. Sham and M. G. Clark, J. Chem. Sot., Dalton Trans. 1976,643. 18. P. G. Harrison, K. Lambert, T. J. King and B. Majee, J. Chem. Sot., Dalton Trans. 1983,363.