Discrete molecular and extended polymeric copper(I) halide complexes of tetradentate thioether macrocycles

A series of complexes of copper(I) halides with either [12]aneS(4) (1,4,7,10-tetrathiacyclododecane) or [16]aneS(4) (1,5,9,13-tetrathiacyclohexadecane) have been synthesized, characterised and their crystal structures determined. Discrete molecular entities of formula [CuX([12]aneS(4))] (X=Cl, Br or I) were isolated from solutions containing a 1:1 metal:ligand stoichiometry. In [CuX([12]aneS(4))] (X=Br or I) the copper(I) centres adopt a rare square pyramidal geometry. Located on fourfold axes of symmetry, the copper(I) centres are co-ordinated by one halide ion [Cu-Br 2.4209(11) or Cu-I 2.573(5) Angstrom] and four sulfur atoms [2.5386(12) (X=Br) and 2.521(5) Angstrom (X=I)]. In contrast, the copper(I) centres in [CuCl([12]aneS(4))] adopt the more common tetrahedral co-ordination geometry, which is provided by one chloride ion [Cu-Cl 2.2666(13) Angstrom] and three sulfur donors [Cu-S 2.3331(13), 2.3326(13), 2.4720(11) Angstrom]. Polymeric materials, [Cu4Br4([12]aneS(4))(2)](infinity), [Cu4I4([12]aneS(4))](infinity) and [Cu2I2([16]aneS(4))](infinity), were obtained from reactions in which metal:ligand stoichiometries of 2:1 and 4:1 were used. [Cu4Br4([12]aneS(4))(2)](infinity) contains a previously uncharacterised copper(I) halide motif of formula Cu4X4 which is derived from the common Cu4X4 cubane tetramer and the Cu4X4 step-cubane tetramer. These Cu4X4 clusters are linked by [12]aneS(4) molecules to generate a two-dimensional framework [Cu-Br 2.410(2)-2.539(2); Cu-S 2.318(3)-2.385(3) Angstrom]. In [Cu4I4([12]aneS(4))](infinity), Cu4I4 cubane tetramers are linked by tetradentate [12]aneS(4) molecules to give a two-dimensional sheet structure [Cu-I 2.602(1)-3.021(1); Cu-S 2.285(1)]. In [Cu2I2([16]aneS(4))](infinity) an infinite three-dimensional co-ordination polymer comprising Cu2I2 rhomboid dimers linked by tetradentate [16]aneS(4) molecules is formed [Cu-I 2.5972(9)-2.6702(9); Cu-S 2.292(2)-2.357(2) Angstrom]. The Cu2I2 moiety acts as a pseudo-square planar linker while the bridging [16]aneS(4) units afford tetrahedral building blocks to give overall a PtS type structure for the polymer.