Reactivity of CuI and CuBr toward Dialkyl Sulfides RSR: From Discrete Molecular Cu₄I₄S₄ and Cu₈I₈S₆ Clusters to Luminescent Copper(I) Coordination Polymers

The 1D coordination polymer (CP) [(Me₂S)₃{Cu₂(μ-I)₂}]_<i>n</i> (<b>1</b>) is formed when CuI reacts with SMe₂ in <i>n</i>-heptane, whereas in acetonitrile (MeCN), the reaction forms exclusively the 2D CP [(Me₂S)₃{Cu₄(μ-I)₄}]_<i>n</i> (<b>2</b>) containing “flower-basket” Cu₄I₄ units. The reaction product of CuI with MeSEt is also solvent-dependent, where the 1D polymer [(MeSEt)₂{Cu₄(μ₃-I)₂(μ₂-I)₂}­(MeCN)₂]_<i>n</i> (<b>3</b>) containing “stepped-cubane” Cu₄I₄ units is isolated in MeCN. In contrast, the reaction in <i>n</i>-heptane affords the 1D CP [(MeSEt)₃{Cu₄(μ₃-I)₄}]_<i>n</i> (<b>4</b>) containing “closed-cubane” Cu₄I₄ clusters. The reaction of MeSPr with CuI provides the structurally related 1D CP [(MeSPr)₃{Cu₄(μ₃-I)₄}]_<i>n</i> (<b>5</b>), for which the X-ray structure has been determined at 115, 155, 195, 235, and 275 K, addressing the evolution of the metric parameters. Similarly to <b>4</b> and the previously reported CP [(Et₂S)₃{Cu₄(μ₃-I)₄}]_<i>n</i> (<i>Inorg. Chem.</i> <b>2010</b>, <i>49</i>, 5834), the 1D chain is built upon closed cubanes Cu₄(μ₃-I)₄ as secondary building units (SBUs) interconnected via μ-MeSPr ligands. The 0D tetranuclear clusters [(L)₄{Cu₄(μ₃-I)₄}] [L = EtSPr (<b>6</b>), Pr₂S (<b>7</b>)] respectively result from the reaction of CuI with EtSPr and <i>n</i>-Pr₂S. With <i>i</i>-Pr₂S, the octanuclear cluster [(<i>i</i>-Pr₂S)₆{Cu₈(μ₃-I)₃}­(μ₄-I)₂}] (<b>8</b>) is formed. An X-ray study has also been performed at five different temperatures for the 2D polymer [(Cu₃Br₃)­(MeSEt)₃]_<i>n</i> (<b>9</b>) formed from the reaction between CuBr and MeSEt in heptane. The unprecedented framework of <b>9</b> consists of layers with alternating Cu­(μ₂-Br)₂Cu rhomboids, which are connected through two μ-MeSEt ligands to tetranuclear open-cubane Cu₄Br₄ SBUs. MeSPr forms with CuBr in heptane the 1D CP [(Cu₃Br₃)­(MeSPr)₃]_<i>n</i> (<b>10</b>), which is converted to a 2D metal–organic framework [(Cu₅Br₅)­(μ₂-MeSPr)₃]_<i>n</i> (<b>11</b>) incorporating pentanuclear [(Cu₅(μ₄-Br)­(μ₂-Br)] SBUs when recrystallized in MeCN. The thermal stability and photophysical properties of these materials are also reported