Distorted <i>commo</i>-Cobaltacarboranes Based on the 5,6-Dicarba-<i>nido</i>-decaborane(12): The First Bimetal Cobalt–Copper Zwitterion-Containing Cluster with Four (B–H)₄···Cu Bonds Not Showing Fluxional Behavior in Solution

Treatment of a recently reported complex [Ph₄P]­[<i>closo,nido-</i>CoH­(2,4-C₂B₈H₁₀)­(7,8-C₂B₈H₁₁)] (<b>1</b>) either by H₂O₂ in acetone or NaH in THF leads to the loss of both the bridging and terminal hydrides yielding the diamagnetic salt of an anionic <i>commo</i>-cobaltacarborane [Ph₄P]­[Co­(2,4-<i>isonido</i>-C₂B₈H₁₀)₂] (<b>2</b>) with the {CoC₂B₈}-cluster units adopting a distorted skeletal geometry of the <i>isonido</i>-type. The anionic <i>commo</i> complex <b>2</b> reacts with in situ generated cationic [CuPPh₃]⁺ species to give stable copper–cobalt zwitterion [Ph₃PCu]­[Co­(2,4-<i>isonido</i>-C₂B₈H₁₀)₂] (<b>3</b>) with four two-electron, three-center (B–H)₄···Cu bonds, and exhibits no fluxional behavior in solution. Complex <b>3</b>, at the same time, in CH₂Cl₂ in the presence of 2-fold excess of PPh₃ readily converts to a new anionic species [(Ph₃P)₃Cu]­[Co­(2,4-<i>isonido</i>-C₂B₈H₁₀)₂] (<b>4</b>) which retains initial <i>isonido</i> geometry. All newly obtained diamagnetic <i>commo</i> complexes were characterized by a combination of analytical and multinuclear NMR spectroscopic data and by single-crystal X-ray diffraction studies of complexes <b>2</b> and <b>3</b>

Coordination Chemistry of Mercury-Containing Anticrowns. Complexation of Perfluoro‑<i>o</i>,<i>o</i>′‑biphenylenemercury with <i>o</i>‑Xylene and Acetonitrile and the First X‑ray Diffraction Evidence for Its Trimeric Structure

The paper reports the first X-ray diffraction data evidencing the cyclic trimeric structure of the earlier synthesized octafluoro-<i>o</i>,<i>o</i>′-biphenylenemercury (<b>8</b>), being of considerable interest as a potential anticrown. The conclusion on the trimeric (<i>o</i>,<i>o</i>′-C₆F₄C₆F₄Hg)₃ structure of this mercuracycle is based on an X-ray structural analysis of its <i>o</i>-xylene and acetonitrile complexes {[(<i>o</i>,<i>o</i>′-C₆F₄C₆F₄Hg)₃]­(<i>o</i>-Me₂C₆H₄)₂} (<b>9</b>) and {[(<i>o</i>,<i>o</i>′-C₆F₄C₆F₄Hg)₃]­(MeCN)₃} (<b>10</b>), which were obtained from <b>8</b> in an analytically pure state and fully characterized. Complex <b>9</b> contains two <i>o</i>-xylene species per one molecule of <b>8</b> and forms in the crystal infinite chains consisting of alternating mercuramacrocycle units and bridging <i>o</i>-xylene ligands. One more <i>o</i>-xylene molecule in each macrocyclic fragment of the chain serves as a terminal ligand. Both bridging and terminal molecules of <i>o</i>-xylene are coordinated in all cases with only one Hg site of the corresponding mercuracycle. The back transformation of complex <b>9</b> into <b>8</b> and <i>o</i>-xylene occurs on its heating in a vacuum at 100–120 °C for 2 h. In contrast to <b>9</b>, complex <b>10</b>, containing three acetonitrile ligands per one molecule of <b>8</b>, has a discrete structure in the crystal. In this complex, two of three acetonitrile species are bonded to one and the same Hg center of <b>8</b>, whereas the third MeCN species is coordinated with the other Hg atom of the mercuramacrocycle

Coordination Chemistry of Anticrowns. Synthesis and Structures of Double-Decker Sandwich Complexes of the Three-Mercury Anticrown (<i>o</i>‑C₆F₄Hg)₃ with Halide Anions Containing and Not Containing Coordinated Dibromomethane Molecules

The interaction of the three-mercury anticrown (<i>o</i>-C₆F₄Hg)₃ (<b>1</b>) with [PPh₄]­[BF₄] in methanol at room temperature leads to fluoride anion transfer from BF₄^– to <b>1</b> with the formation of a fluoride complex, [PPh₄]­{[(<i>o</i>-C₆F₄Hg)₃]₂F}, having a double-decker sandwich structure. The fluoride ion in this unique adduct is disposed between the mutually parallel planes of the central nine-membered rings of the anticrown units and cooperatively coordinated by all six Hg sites. The iodide anion also forms a double-decker sandwich in the interaction with <b>1</b>, but this sandwich, [PPh₄]­{[(<i>o</i>-C₆F₄Hg)₃]₂I}, has a wedge-shaped geometry. The reaction of <b>1</b> with [^<i>n</i>Bu₄N]Cl in dibromomethane at −15 °C affords a complex, [^<i>n</i>Bu₄N]­{[(<i>o</i>-C₆F₄Hg)₃]₂Cl­(CH₂Br₂)₂}, containing one chloride anion and two coordinated CH₂Br₂ species per two molecules of <b>1</b>. A similar bromide complex of <b>1</b>, containing two coordinated CH₂Br₂ moieties, has also been synthesized and structurally characterized. Both compounds represent wedge-shaped double-decker sandwiches wherein the halide anion is simultaneously bonded to all Hg centers of the anticrown molecules. The dibromomethane species in the isolated adducts are also arranged in the space between the mercuramacrocycles. One of these species is coordinated by each of its bromine atoms to a single Hg site of the adjacent macrocycle while the other interacts by only one bromine atom with a Hg center of the neighboring molecule of <b>1</b>

Coordination Chemistry of Anticrowns. Synthesis and Structures of Double-Decker Sandwich Complexes of the Three-Mercury Anticrown (<i>o</i>‑C₆F₄Hg)₃ with Halide Anions Containing and Not Containing Coordinated Dibromomethane Molecules

The interaction of the three-mercury anticrown (<i>o</i>-C₆F₄Hg)₃ (<b>1</b>) with [PPh₄]­[BF₄] in methanol at room temperature leads to fluoride anion transfer from BF₄^– to <b>1</b> with the formation of a fluoride complex, [PPh₄]­{[(<i>o</i>-C₆F₄Hg)₃]₂F}, having a double-decker sandwich structure. The fluoride ion in this unique adduct is disposed between the mutually parallel planes of the central nine-membered rings of the anticrown units and cooperatively coordinated by all six Hg sites. The iodide anion also forms a double-decker sandwich in the interaction with <b>1</b>, but this sandwich, [PPh₄]­{[(<i>o</i>-C₆F₄Hg)₃]₂I}, has a wedge-shaped geometry. The reaction of <b>1</b> with [^<i>n</i>Bu₄N]Cl in dibromomethane at −15 °C affords a complex, [^<i>n</i>Bu₄N]­{[(<i>o</i>-C₆F₄Hg)₃]₂Cl­(CH₂Br₂)₂}, containing one chloride anion and two coordinated CH₂Br₂ species per two molecules of <b>1</b>. A similar bromide complex of <b>1</b>, containing two coordinated CH₂Br₂ moieties, has also been synthesized and structurally characterized. Both compounds represent wedge-shaped double-decker sandwiches wherein the halide anion is simultaneously bonded to all Hg centers of the anticrown molecules. The dibromomethane species in the isolated adducts are also arranged in the space between the mercuramacrocycles. One of these species is coordinated by each of its bromine atoms to a single Hg site of the adjacent macrocycle while the other interacts by only one bromine atom with a Hg center of the neighboring molecule of <b>1</b>

Supramolecular Design of the Trinuclear Silver(I) and Copper(I) Metal Pyrazolates Complexes with Ruthenium Sandwich Compounds via Intermolecular Metal−π Interactions

The interaction of copper­(I) and silver­(I) macrocyclic pyrazolates with aromatic ligands of ruthenium sandwiches (Cp*RuInd, CpRuInd, and Ind₂Ru) in solution is shown for the first time. The similar mode of coordination of macrocycles to the C₆ fragment of indenyl ligand was found both in the solution and in the solid state. Complexation of macrocycles with the nonencumbered sandwiches (CpRuInd, Ind₂Ru) leads to the formation of infinite stacks via alternating molecules of macrocycles and sandwich compounds as one-dimensional coordination polymers with a regular structure. Coordination mode of the indenyl ligand is independent of the second part of the ruthenium sandwich as well as of the aromatic ligand coordinated to another face of the macrocycle. The general principle of macrocycle supramolecular packing suggests coordination of two ligands on both faces of the macrocycle