Abstract
New stable divalent heterocyclic species [SnL1; 1, SnL2; 2] using ONNO and SNNS tetradentate Schiff bases; N,N′-bis(salicylidene)-1,2-bis(o-aminophenoxy)ethane (H2L1) and N,N′-bis(2-aminothiophenol)-1,4-bis(2-carboxaldehydephenoxy)butane (H2L2) were obtained in good yields by alcolysis of the M-N bonds of the divalent precursor Sn[N(SiMe3)2]2 by diols. They have been isolated as solids at ambient temperature and are monomeric. FT-IR, 1H and 119Sn-NMR spectra are suggestive of N … M intramolecular coordination. Then the synthesis and characterization of the new stable mono and cis-disubstituted Sn(II) chromium and tungsten carbonyl complexes [L1Sn]M(CO)5 (M= Cr, 3; W, 4); [L2Sn]M(CO)5 (M= Cr, 5; W, 6); cis-[L1Sn]2M(CO)4 (M= Cr, 7; W, 8) and cis-[L2Sn]2M(CO)4 (M= Cr, 9; W, 10) are described. Pentacarbonyl complexes (3–6) were obtained in high yields by treatment of the M(CO)5THF (M= Cr, W) intermediates with the divalent species [SnL1; 1, SnL2; 2] and tetracarbonyl complexes (7–10) were synthesized by the photochemical reactions of [LnSn]M(CO)5 with [LnSn] (n = 1, 2). Each of the new carbonyl complexes has been characterized by IR, 1H, 13C, 119Sn-NMR spectroscopy, and mass spectrometry. The sigma donor and pi acceptor ability of the divalent tin species [SnL1, 1; SnL2, 2] as ligands in the transition metal carbonyl complexes (3–10) is discussed by comparing ν(CO) stretching frequencies.
Acknowledgments
This work was financially supported by the Scientific Research Foundation of Dokuz Eylul University (project number: 2008.KB.FEN.001). The authors thank TUBİTAK for allocation of time for NMR, mass spectra and elemental analyses. They also thank the Graduate School of Natural and Applied Sciences of Dokuz Eylul University.