Supramolecular Isomerism in a Cadmium Bis(<i>N</i>-Hydroxyethyl, <i>N</i>-isopropyldithiocarbamate) Compound: Physiochemical Characterization of Ball (<i>n</i> = 2) and Chain (<i>n</i> = ∞) Forms of {Cd[S₂CN(iPr)CH₂CH₂OH]₂·solvent}_<i>n</i>

Abstract

Needles of [{Cd[S 2 CN(iPr)CH 2 CH 2 OH] 2 } 3 ·MeCN] ∞ ( 2 ) were harvested from a dry acetonitrile solution of Cd[S 2 CN(iPr)CH 2 CH 2 OH] 2 after one or two days and proved to be a coordination polymer in which all dithiocarbamate ligands are μ 2,κ 2 -tridentate, bridging two cadmium atoms and simultaneously chelating one of these. If the same solution was allowed to stand for at least several days, 2 is replaced by blocks comprising a supramolecular isomer of 2, dimeric 1, with formula {Cd[S 2 CN(iPr)CH 2 CH 2 OH] 2 } 2 ·2H 2 O·2MeCN, and two ligands coordinating μ 2,κ 2 as in 2 and the other two purely κ 2 -chelating. The time dependency correlates with the pivotal role of water in driving the conversion of “chain” 2 to “ball” 1; crystals of 2 could not be isolated from “wet” acetonitrile. When each of 1 and 2 are dissolved in solution, they exhibit comparable spectroscopic attributes ( 1 H, 13 C, and 113 Cd NMR and UV/vis), indicating the solution structures are the same. Both 1 and 2 are luminescent in the solid state with 1 being significantly brighter than 2 . Greenockite CdS nanoparticles are generated by the thermal decomposition of both 1 and 2 .