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

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

1,4-Bis(arylthio)but-2-enes as Assembling Ligands for (Cu₂X₂)_<i>n</i> (X = I, Br; <i>n</i> = 1, 2) Coordination Polymers: Aryl Substitution, Olefin Configuration, and Halide Effects on the Dimensionality, Cluster Size, and Luminescence Properties

CuI reacts with <i>E</i>-PhS­(CH₂CHCHCH₂)­SPh, <b>L1</b>, to afford the coordination polymer (CP) [Cu₂I₂­{μ-<i>E</i>-PhS­(CH₂CHCHCH₂)­SPh}₂]_<i>n</i> (<b>1a</b>). The unprecedented square-grid network of <b>1</b> is built upon alternating two-dimensional (2D) layers with an ABAB sequence and contains rhomboid Cu₂(μ₂-I)₂ clusters as secondary building units (SBUs). Notably, layer A, interconnected by bridging <b>L1</b> ligands, contains exclusively dinuclear units with short Cu···Cu separations [2.6485(7) Å; 115 K]. In contrast, layer B exhibits Cu···Cu distances of 2.8133(8) Å. The same network is observed when CuBr reacts with <b>L1</b>. In the 2D network of [Cu₂Br₂­{μ-<i>E</i>-PhS­(CH₂CHCHCH₂)­SPh}₂]_<i>n</i> (<b>1b</b>), isotype to <b>1a</b>, one square-grid-type layer contains Cu₂(μ₂-Br)₂ SBUs with short Cu···Cu contacts [2.7422(6) Å at 115K], whereas the next layer incorporates exclusively Cu₂(μ₂-Br)₂ SBUs with a significantly longer Cu···Cu separation [2.9008(10) Å]. The evolution of the crystallographic parameters of <b>1a</b> and <b>1b</b> was monitored between 115 and 275 K. Conversely, the isomeric <i>Z</i>-PhS­(CH₂CHCHCH₂)­SPh ligand <b>L2</b> reacts with CuI to form the 2D CP [Cu₄(μ₃-I)₄(μ-<i>­Z</i>-PhS­(CH₂CHCHCH₂)­SPh}₂]_<i>n</i> (<b>2a</b>) with closed-cubane SBUs. A dinuclear zero-dimensional complex [Cu₂Br₂­{μ-<i>Z</i>-PhS­(CH₂CHCHCH₂)­SPh}₂] (<b>2b</b>) is formed when CuBr is reacted with <b>L2</b>. Upon reaction of <i>E</i>-TolS­(CH₂CHCHCH₂)­STol, <b>L3</b>, with CuI, the 2D CP [{Cu­(μ₃-I)}₂­(μ-<b>L3</b>)]_<i>n</i> containing parallel-arranged infinite inorganic staircase ribbons, is generated. When CuX reacts with <i>Z</i>-TolS­(CH₂CHCHCH₂)­STol, <b>L4</b>, the isostructural 2D CPs [Cu₂X₂­{μ-<i>Z</i>-TolS­(CH₂CHCHCH₂)­STol}₂] <b>(4a</b> X = I; <b>4b</b> X = Br) are formed. In contrast to the CPs <b>1a,b</b>, the layers based on rhombic grids of <b>4a,b</b> incorporate Cu₂(μ₂-X)₂ SBUs featuring uniformly identical Cu···Cu distances within each layer. The TGA traces showed that all these materials are stable up to ∼200 °C. Moreover, the photophysical properties have been studied, including absorption, emission, excitation spectra, and emission lifetimes at 298 and 77 K. The spectra were interpreted using density functional theory (DFT) and time-dependent DFT calculations

Copper(I) Halides (X = Br, I) Coordinated to Bis(arylthio)methane Ligands: Aryl Substitution and Halide Effects on the Dimensionality, Cluster Size, and Luminescence Properties of the Coordination Polymers

Bis­(phenylthio)­methane (<b>L1</b>) reacts with CuI to yield the 1D-coordination polymer [{Cu₄(μ₃-I)₄}­(μ-<b>L1</b>)₂]_<i>n</i> (<b>1</b>) bearing cubane Cu₄I₄ clusters as connecting nodes. The crystal structures at 115, 155, 195, and 235 K provided evidence for a phase transition changing from the monoclinic space group <i>C</i>2/<i>c</i> to <i>P</i>2₁/<i>c</i>. The self-assembly process of CuI with bis­(<i>p</i>-tolylthio)­methane (<b>L2</b>), bis­(4-methoxyphenylthio)­methane (<b>L3</b>), and bis­(4-bromo-phenylthio)­methane (<b>L4</b>) affords the 1D-coordination polymers [{Cu₄(μ₃-I)₄}­(μ-<b>L<i>x</i></b>)₂]_<i>n</i> (<i>x</i> = 2, 3, or 4). Compounds <b>2</b> and <b>4</b> are isostructural with <i>C</i>2/<i>c</i> low temperature polymorph of <b>1</b>, whereas the inversion centers and 2-fold axes are lost in <b>3</b> (space group <i>Cc</i>). The use of bis­(<i>m</i>-tolylthio)­methane (<b>L5</b>) has no impact on the composition and overall topology of the resulting 1D ribbon of [{Cu₄(μ₃-I)₄}­(μ-<b>L5</b>)₂]_<i>n</i> (<b>5</b>). Even the coordination of the sterically crowded dithioether bis­(5-<i>tert</i>-butyl-2-methylphenylthio)­methane (<b>L8</b>) does not alter the network topology generating the 1D polymer [{Cu₄(μ₃-I)₄}­(μ-<b>L8</b>)₂]_<i>n</i> (<b>8</b>). The 1D polymer [{Cu­(μ₂-Br)₂Cu}­(<b>L1</b>)₂] (<b>9</b>) results from the coordination of <b>L1</b> with CuBr in a 1:1 metal-to-ligand ratio. In contrast to the mean Cu···Cu distances, which are <2.8 Å noted for the Cu₄(μ₃-I)₄ clusters in the 1D polymers <b>1</b>–<b>8</b>, the Cu···Cu contact within the Cu­(μ₂-Br)₂Cu rhomboids of <b>9</b> [2.9194(8) Å] is above the sum of the van der Waals radii of two Cu atoms. The structural arrangement of 1D polymer [{Cu­(μ₂-Br)₂Cu}­(<b>L3</b>)₂]_<i>n</i> (<b>11</b>) is quite similar to that of <b>9</b>. While the reaction of CuBr with <b>L5</b> results in a similar 1D polymer [{Cu­(μ₂-Br)₂Cu}­(<b>L5</b>)₂]_<i>n</i> (<b>12</b>), the reaction of CuBr with <b>L2</b> leads to the dinuclear complex [{Cu­(μ₂-Br)₂Cu}­(η¹-<b>L2</b>)₄] (<b>10</b>) ligated by four pendent bis­(<i>p</i>-tolylthio)­methane ligands. The ligation of bis­(<i>o</i>-tolylthio)­methane, <b>L6</b>, on CuBr also yields a discrete complex [{Cu­(μ₂-Br)₂Cu}­(MeCN)₂(η¹-<b>L6</b>)₂] (<b>13</b>) bearing MeCN and dangling dithioether ligands. A strong luminescence is detected for all CuI polymers, all exhibiting emission lifetimes in the microsecond time scale (i.e., phosphorescence). The polymers containing the Cu₄I₄ core (<b>1</b>–<b>8</b>) exhibit the typically observed low-energy band and sometimes a weaker high-energy band. The nature of the low-energy band was proposed based on literature DFT and TDDFT computations and is predicted to be a mixture of cluster-centered (CC*) and metal/halide-to-ligand charger transfer (M/XLCT). An approximate relationship between the Cu···Cu distance and the emission maxima corroborates the CC* contribution to the nature of the excited states. The emission of the rhomboid-containing materials is assigned to M/XLCT based on literature works on similar motifs