METAL ALKYL AND ARYL COMPOUNDS .47. ORGANOSODIUM COMPOUNDS WITH BENZYL, XYLYL, DIPHENYLMETHYL AND 1-PHENYLETHYL CARBANIONS

Several organosodium compounds with the carbanions benzyl (phenylmethanide), diphenylmethyl (diphenylmethanide), o-xylyl (o-methylphenylmethanide) and 1-phenylethyl (1-phenylethanide) have been synthesized as base adducts with TMEDA (tetramethylethylenediamine) or PMDTA (pentamethyldiethylenetriamine) and studied by X-ray diffraction methods. Their structures are the result of ionic interactions between solvated Na ions and carbanions in combination with steric effects. Always a maximum number of shorter (ca. 260 pm) and longer (up to 300 pm) Na-C contacts is achieved, often by formation of cyclic tetramers or polymer chains. The following compounds have been investigated in detail: [benzylsodium(PMDTA)]n (3), [o-xylylsodium(TNEDA)]4 (4), [diphenylmethylsodium(TMEDA)]4 (5), diphenylmethylsodium(PMDTA) (monomer) (6) and [1-phenylethylsodium(TMEDA)]n (7).