Optical limiting properties of two organometallic half-open cubane-like cluster compounds [(η5-C5Me5)WS3Cu3Br2(EPh3)2] (E=As,P)

Reactions of [PPh4][(η5-C5Me5)WS3] with CuBr and EPh3 (E=As,P) in MeCN gave rise to [(η5-C5Me5)WS3Cu3Br2(EPh3)2] (1: E=As; 2: E=P) in high yield. Single-crystal X-ray analysis revealed that the structure of 1 or 2 consists of a half-open cubane-like [WS3Cu3Br] cluster core where one Cu–Br bond is broken. The optical limiting properties for 1 and 2 in CH2Cl2 were studied with 12 ns and 35 ps laser pulses at 532 nm. The linear transmittance and thresholds at 532 nm laser light for 1 and 2 are 58% and 2.1 J cm−2, and 41% and 1.9 J cm−2, respectively. The optical limiting properties of 1 and 2 are compared with those of known closed cubane-like and nest-like clusters derived from [MS4]2−, [MOS3]2− (M=Mo,W), and [MoSe4]2− anions.