Five-co-ordinated gallium(iir) and indium(ii1) complexes, GaCl[PhC(S)CHC(O)Ph],, GaCI(S,CNR,),

The 1-pyrrolecarbodithioate complexes of tin, PhSnC1-bipyramidal configuration. 1 attains approximately a cis-oc-(SZCNC4H4)z (1) and S~I ( S~C N C~H~)~ (2) have been synthesized tahedral geometry with two bidentate carbodithioate ligands and characterized by IR and NMR spectra ('H, I3C and "'Sn).with the C1 atom and the phenyl group in cis position. Com-6"' Sn suggests hexacoordination for 1 and an even higher plex 2 possesses two bidentate ligands while the other two are coordination number for 2. X-ray structure determinations of essentially anisobidentate leading to a structure between an these as well as of Me2Sn (SzCNC4H4)2 (3) have shown that 3 octahedraon and a dodecahedron. is one of the few known examples with a skew-trapezoidal Despite extensive synthetic and structural reports on metal dialkyldithiocarbamates".2' (R2NCS2),M those containing an aromatic R2N group received much less attention. Work by Bereman and on their transition metal complexes mark the beginning in that direction. Among the few known aromatic dithiolate complexes, those with the pyrrole ligand are especially interesting. And this ligand can be described with the canonical contribution A and B to its ground state. In this case a positive charge at the nitrogen atom would increase considerably the contribution of the dianionic electronic structure B. In addition, this ligand can act as bidentate, anisobidentate, or unidentate. c.Q S--o<--S c;-Q-S-From a recent study of the complete series of tin(1V) 1-pyrrolecarb~thioates[~~, R4 -,,Sn(SOCNC4H4),, an interesting trend has been witnessed for the bonding pattern of this asymmetrical sulfur-containing ligand. There is a change from an essentially unidentate to an anisobidentate behavior tending to become bidentate with concomitant increase in the Sn-0 interaction as n increases. This also reflects the stereoelectronic effect responsible for the molecular structure. It is not clear, however, wether in reference to a typical non-transition metal centre such as tin(1V) these evident features are the consequence of an oxygen-sulfur donor combination of the potentially bidentate ligand and/or the nature of the central tin atom. In this paper, we report on the synthesis of two new tin(1V) 1-pyrrolecarbodithioate complexes, PhSnC1(S2CNC4H4)2 (1) and Sn(S2CNC4H4)4 (2) as well as on their crystal and molecular structures and, in addition, also on the structure of Me2Sn (S2CNC4H4)2 (3)[61.

A series of organotin(1V) maltol complexes R4 -,SnL, (1 -4, 6; x = 1-3) and the dichloro-compound C12SnL2 (5) have been prepared and characterized on the basis of their IR-, IH-, 13C-and l%n-NMR data, While an X-ray crystal structure analysis of PhzSnLz (4) and C12SnL2 (5) reveals distorted cis-octahedral structures, the Me2SnL2 molecule (2) adopts a skew-trapezoidal bipyramidal configuration with a very significant difference in the Sn-O(keto) bond distances. The tris-maltol complex BuSnL, (6) exhibits a distorted pentagonal-bipyramidal geometry with the butyl carbon and a hydroxy oxygen constituting the axial orientations. In view of the rapidly developing field of tin compounds in biological chemistry['], we report in this paper on investigations of the coordination of maltol with organotin(1V) compounds including X-ray crystal and molecular structures of R2SnL2 [R = Ph (4), Me (2)], BuSnL, (6), and C12SnL2 (5). The presence of almost discrete carbonyl and hydroxy groups in the ligand allows us to distinguish a dative bond from the normal covalent bond in reference to the group-14 element tin as suggested recently by Haaland[l01. Results and DiscussionThe complexes 1, 2, and 3 were prepared by reaction of the corresponding organotin chloride with the sodium salt of maltol, NaL, as described in eq. (1). If triphenyltin chloride was allowed to react with maltol in the presence of sodium acetate, cleavage of a tin-carbon bond occurred besides the substitution of its C1 atom furnishing only diphenyltin bis(malto1ate) (4). Similarly, the reaction according to eq. (3) yielded C12SnL2 (5). BuSnL3 (6) was obtained from butylstannoic acid and maltol as shown in eq. (4). The tetramaltolatostannane, SnL4, could not be isolated from the reaction of SnCI4 with 4 equivalents of NaL. All these complexes (Table 1)

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Butyltin triisopropoxide reacts with benzoyl(thiobenzoyl)methane (LH) to yield BuSn(S)L and an organic sulfide 2 instead of the expected BuSnL3. The use of other butyltin(IV) starting materials invariably leads to the same products. From an X‐ray structure determination the tin sulfido complex is found to be a centrosymmetric dimer, [BuSn(S)L]2 (1) with a planar four‐membered Sn2S2 ring containing pentacoordinated tin atoms.

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ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.