N-[2-(4-methoxyphenyltelluro)ethyl]phthalimide (L1):: synthesis, oxidation by ruthenium(III) chloride and ligation with ruthenium(II).: Crystal structures of L1, its oxidized product and of [RuCl2(p-cymene)•L1]

N-[2-(4-methoxyphenyltelluro)ethyl]phthalimide (L-1) synthesized by reacting ArTe- (generated in situ) with N-(2-bro-moethyl)phthalimide, has been characterized structurally. The Te-C(alkyl) (2.147(5) Angstrom) is somewhat longer than Te-C(aryl) (2.111(4) Angstrom). The L-1 on reaction with RuCl3. xH(2)O results in a novel heterocycle, Te-chloro,Te-anisyl-1a-aza-4-oxa-3-tellura-1H,2H,4aH-9-fluorenone (1), which is characterized structurally and is a unique example of a tellura heterocycle containing oxygen as well as nitrogen in the same ring. The oxidation state of Te changes to + IV in the formation of 1. The Te-Cl and Te-O bond lengths in 1 are 2.604(2) and 2.038(4) Angstrom, respectively. The reaction of L-1 with [RuCl2(p-cymene)](2) gives [RuCl2(p-cymene). L-1] (2) which is characterized structurally. The Ru-C (av), Ru-CI and Ru-Te bond lengths are 2.192(1), 2.417(1)-2.434(1) and 2.651(5) Angstrom, respectively. The difference in Te-C(alkyl) and Te-C(aryl) bond lengths is not affected on the ligation of L-1 with ruthenium(II). (C) 2000 Elsevier Science S.A. All rights reserved.