Copper halide-bridged ruthenium telluride carbonyl complexes: Discovery of the semiconducting cluster chain polymer {[PPh4]2[Te 2Ru4(CO)10Cu4Br2Cl 2]·THF∞

Abstract

A new series of Te-Ru-Cu carbonyl complexes was prepared by the reaction of K2TeO3 with [Ru3(CO)12] in MeOH followed by treatment with PPh4X (X = Br, Cl) and [Cu(MeCN) 4]BF4 or CuX (X = Br, C1) in MeCN. When the reaction mixture of K2TeO3 and [Ru3(CO)12] was first treated with PPh4X followed by the addition of [Cu(MeCN)4]BF4, doubly CuX-bridged Te2Ru 4-based octahedral clusters [PPh4]2[Te 2Ru4(CO)10Cu2X2] (X = Br, [PPh4]2[1]; X = Cl, [PPh4J2P]) were obtained. When the reaction mixture of K2TeO3 and [Ru3(CO)12] was treated with PPh4X (X = Br, Cl) followed by the addition of CuX (X = Br, Cl), three different types of CuX-bridged Te-Ru carbonyl clusters were obtained. While the addition of PPh4Br or PPh4Cl followed by CuBr produced the doubly CuBr-bridged cluster 1, the addition of PPh4Cl followed by CuCl led to the formation of the Cu4Cl2bridged bis-TeRu 5-based octahedral cluster compound [PPh4] 2[{TeRu5(CO)14}2Cu 4Cl2] ([PPh4]2[3]). On the other hand, when the reaction mixture of K2TeO3 and [Ru 3(CO)12] was treated with PPh4Br followed by the addition of CuCl, the Cu(Br)CuCl-bridged Te2Ru4-based octahedral cluster chain polymer {[PPh4]2(Te2Ru 4(CO)10-Cu4Br2Cl2)THFL ({[PPh4]2[4]·[THF)∞) was produced. The chain polymer {[PPh4]2;[4]·THF)· is the first ternary Te-Ru-Cu cluster and shows semiconducting behavior with a small energy gap of about 0.37 eV. It can be rationalized as resulting from aggregation of doubly CuX-bridged clusters 1 and 2 with two equivalents of CuCl or CuBr, respectively. The nature of clusters 1-4 and the formation and semiconducting properties of the polymer of 4 were further examined by molecular orbital calculations at the B3LYP level of density functional theory. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA,.