title: Formation of dimeric and polymeric W/Cu/S clusters via degradation or expansion of the cluster core in [Et4N]4[WS4Cu4I6].
abstract: The reactions of a precursor cluster [Et4N]4[WS4Cu4I6] (1) with two equiv. of 1,1'-(1,4-butanediyl)bis(3,5-dimethyl-pyrazole) (bbd) or 1,3,5-tris(3,5-dimethyl-pyrazolyl-1-ylmethyl)-2,4,6-trimethylbenzene (tdtb) in MeCN/DMF afforded the dimeric clusters [WS4Cu3I(mut-bbd)]2 (2) and [{WS4Cu3(tdtb)}2(mu-I)2].2DMF (3.2DMF), respectively. Solvothermal reactions of 1 with two equiv. of bbd in MeCN/DMF at 90 degrees C for 24 h resulted in the formation of the dimeric cluster [Et4 N]6[{WS4Cu5(mu-I)2I4}2(mu-bbd)] (4) while those of 1 with two equiv. of 1,3,5-tris(imidazol-1-ylmethyl)-2,4,6-trimethylbenzene (titb) in DMF at 120 degrees C afforded the polymeric cluster {[WS4Cu2(titb)].0.5H2O}n (5). Compounds 2-5 were characterized by elemental analysis, IR, UV-vis, 1H NMR and single-crystal X-ray crystallography. Compound 2 has a double nido-shaped structure in which two nido-shaped [WS4Cu3] cores are connected by a pair of bbd ligands while 3 has a double butterfly-shaped structure in which two [WS4Cu3(tdtb)] fragments are linked by two bridging iodides. Compound 4 has a double-double half-open cubane-like structure in which a couple of double half-open cubane-like [WS4Cu5] cores are bridged by one bbd ligand. Compound 5 has a unique two-fold interpenetrated 3D (10(2) x 12)core(10(2) x 12)tib network in which each linear [WS4Cu2] core acts as a T-shaped 3-connecting node and each titb ligand works as a trigonal pyramidal 3-connecting node. The core structures of 2-5 are different from the saddle-shaped [WS4Cu4] core of 1, which may be attributed to the degradation or expansion of the cluster core of 1 during the reactions. In addition, the third-order non-linear optical (NLO) properties of 1-4 in DMF were also investigated by using Z-scan techniques at 532 nm.
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Suzhou University, Suzhou 215123, PR China.
authors.forename: Yu-Jian
authors.initials: YJ
authors.lastname: Huang
authors.forename: Ying-Lin
authors.initials: YL
authors.lastname: Song
authors.forename: Yang
authors.initials: Y
authors.lastname: Chen
authors.forename: Hong-Xi
authors.initials: HX
authors.lastname: Li
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Lang