Copper(I) pseudohalide coordination polymers containing macrocyclic methyleycloarsoxane (CH3AsO)n (n=4, 5) or 1,7-dithia-18-crown-6 bridging units

Treatment of an acetonitrile solution of CuCN with methyleycloarsoxane (CH3AsO)(n) at 110 degrees C affords the coordination polymer (3)(infinity)[CuCN {cyclo-(CH3AsO)(4)}] (1), in which infinite CuCN zigzag chains are linked by mu-As-1,As-3 cyclotetramers (CH3AsO)(4) into an open 3-D framework. Under similar solvothermal conditions, reaction of CuSCN with (CH3AsO), in the presence of KSCN leads to metal-mediated ring expansion of the cycloarsoxane to yield the complex (1)(infinity)[{K[cyclo-(CH3AsO)(5)](2)}Cu(NCS)(2)] (2). This contains discrete [Cu(NCS-kappa N)(2){cyclo-(CH3AsO)(5)kappa As}(2)](-) anions that bridge kappa(10)0 coordinated potassium cations into infinite chains. In contrast, the structure directing role of the [K(1,7DT18C6)(2)](+) sandwich building units for the solvothermal product (3)(infinity)[{K(1,7DT18C6)(2)}Cu-6(CN)(7)](3) (1,7DT18C6 = 1,7-dithia-18-crown-6) leads to formation of an open (3)(infinity)[{Cu-6(CN)(7)}(-)] framework. Individual [K(1,7DT18C(6))(2)](+) moieties bridge Cu Atoms in a,mu-S-1,S-7 mode and are encapsulated within the large [Cu-26(CN)(28)](2-) cages of the cyanocuprate(I) network.