Construction of [CunIn]-based coordination polymers via flexible benzimidazolyl-based ligands

Four new [Cu n I n ]-based coordination polymers, [{ Cu 4 (µ 3 -I) 4 (mbbm) 2 }·2DMF] n ( 1 ), [(CuI) 2 (mbbm) 2 ] n ( 2 ), [{Cu 2 (µ-I) 2 -(ebbm) 2 }·2MeCN] n ( 3 ), and [Cu 2 (µ-I) 2 (prbbm) 2 ] n ( 4 ), were prepared from solvothermal reactions of CuI with three flexible ligands [(bzim)(CH 2 ) n (bzim)] (bzim = benzimidazole; n = 1, mbbm; n = 2, ebbm; n = 3, prbbm). These compounds were characterized by elemental analysis, IR and X-ray crystallography. 1 consists of cubanelike [Cu 4 (µ 3 -I) 4 ] fragments that link the neighboring ones via mbbm bridges to form a 1D ladder-type chain. 2 contains mononuclear [CuI] fragments that are bridged by mbbm ligands to yield a 1D zigzag chain. 3 or 4 contains a [Cu 2 (µ-I) 2 ] dimeric fragment, which works as a four-connecting node to link its four equivalent ones to form a 2D (4,4) network ( 3 ) or acts as a two-connecting node to connect its two equivalent ones via two pairs of prbbm bridges to form a 1D double chain ( 4 ). The photoluminescent properties of 1–4 in the solid state at ambient temperature were investigated.