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The condensation of two molecules of 3,s-di-tert-butylcatechol (dbc) with ammonia under oxidizing conditions is believed to proceed via a keto-imine radical. Further condensation, and subsequent reaction with tin(I1) or lead(I1) halides, yields complexes of identical composition, M [dbqdi],, where dbqdi is 3,5-di-tertbutyl-1,2-quinone-1-(2-hydroxy-3,5-di-tert-butylphenyl)imine anion; this name is used without prejudice as to the actual structure of the ligand. The two compounds differ in crystallographic and magnetic properties, and ESR measurements show that the tin compound has a triplet ground state. Both involve six-coordination of the metal in a distorted environment; tin is in the +IV state, but lead is +II, and there are corresponding differences in the form of the ligand. For snIv(dbqdi),, the crystal parameters are orthorhombic, space group C222,, a = 19.597(4), b = 24.375(4), c = 23.755(6) A, Z = 8, and R = 0.073 for 1405 unique reflections. For pbU(dbqdi),, monoclinic, space group P2,ln, a = 14.56(1), b = 25.967(9), c = 15.13(1) A, P = 99.81(7)', Z = 4, R = 0.065 for 491 1 unique reflections. The different complexation behaviour is shown to be a consequence of the redox properties of the two metallic elements.Key words: tin, lead, ESR, coordination chemistry, electron transfer.Resume : On croit gtntralement que la condensation de deux moltcules de 3,s-di-tert-butylcattchol (dbc) avec de I'ammoniac, dans des conditions oxydantes, se produit par le biais d'un radical ctto-imine. Une condensation substquente, avec rtaction ulterieure avec des halogenures d1Ctain(II) ou de plomb(II), fournit des complexes de composition identique, M(dbqdi),, dans lesquels dbqdi est l'anion 3,s-di-tert-butyl-1.2-quinone-1-(2-hydroxy-3,s-di-tert-butylphtny1)imine; on utilise ce nom sans tgard B la structure rtelle du coordinat. Les proprietts cristallographiques et magnetiques des deux composts sont differentes et les mesures de RPE indiquent que le derive de l'ttain possbde une ttat fondamental triplet. Les deux impliquent un niveau de coordination de six pour le metal, avec un environnement dtformt; l'ttain est dans un &tat +IV alors que pour le plomb il est de +I1 et on peut observer des differences correspondantes dans le forme du coordinat. Pour le snIv(dbqdi),, les cristaux sont orthorhombiques, groupe d'espace C222,, avec a = 19,597(4), b = 24,375(4) et c The reactions of substituted orthobenzoquinones with main group elements, or the low oxidation state derivatives of such elements, have been the subject of a number of recent papers from this laboratory. In general, the products of these processes are the appropriate catecholate or semiquinone derivatives, which have been characterized by spectroscopic and crystallographic methods. An important feature of these results is that the redox reactions in question have been shown to be one-electron transfer processes (1).We have now extended this research to an investigation of the structure of the compounds formed when tin or lead in the +I1 state react with a ...

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. HABEEB, and DESAIS G. TUCK. Can, J. Chem. 55. 1527Chem. 55. (1977. The X-ray photoelectron spectra (metal and halogen energy levels) have been recorded for binary halides of indium in the +I; +II, and t I11 states, and for anionic halide corilplexes of indium (1) and (111). The results are internally consistent in terms of the relation between metal and ligand levels. but lattice effects prevent any detailed interpretation of indium levels in terms of oxidation state, ligand electronegativity, andjor coordination number.

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