Three types of unusual cagelike copper(II) methylsilsesquioxanes, namely, nona- [(MeSiO)(CuO)] 1, hexa- [(MeSiO)(HO)(CuO)(CHN)(MeSiO)(HO)(CHCOO)(CuO)(CHN)] 2, [(MeSiO)(CuO)(MeO)(CHN)] 3, and trinuclear [(MeSiO)(CuO)(CHN)] 4, were obtained in 44%, 27%, 20%, and 16% yields, respectively. Nuclearity and structural fashion of products was controlled by the choice of solvent system and ligand, specifically assisting the assembling of cage. Structures of 1-4 were determined by single-crystal X-ray diffraction analysis. Compounds 1 and 4 are the first cage metallasilsesquioxanes, containing nine and three Cu ions, respectively. Product 1 is the first observation of nonanuclear metallasilsesquioxane ever. Unique architecture of 4 represents early unknown type of molecular geometry, based on two condensed pentamembered siloxane cycles. Topological analysis of metal clusters in products 1-4 is provided. Complex 1 efficiently catalyzes oxidation of alcohols with tert-butylhydroperoxide TBHP to ketones or alkanes with HO to alkyl hydroperoxides in acetonitrile.

Interconversion between coordinated diphosphinomethane and diphosphinomethanide moieties can be used as a new tool for metal–ligand cooperation.

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Dimethylamine-borane (DMAB) acid/base properties, its dihydrogen-bonded (DHB) complexes and proton transfer reaction in nonaqueous media were investigated both experimentally (IR, UV/vis, NMR, and X-ray) and theoretically (DFT, NBO, QTAIM, and NCI). The effects of DMAB concentration, solvents polarity and temperature on the degree of DMAB self-association are shown and the enthalpy of association is determined experimentally for the first time (-ΔH°assoc = 1.5-2.3 kcal/mol). The first case of "improper" (blue-shifting) NH···F hydrogen bonds was observed in fluorobenzene and perfluorobenzene solutions. It was shown that hydrogen-bonded complexes are the intermediates of proton transfer from alcohols and phenols to DMAB. The reaction mechanism was examined computationally taking into account the coordinating properties of the reaction media. The values of the rate constants of proton transfer from HFIP to DMAB in acetone were determined experimentally [(7.9 ± 0.1) × 10(-4) to (1.6 ± 0.1) × 10(-3) mol(-1)·s(-1)] at 270-310 K. Computed activation barrier of this reaction ΔG(‡theor)298 K(acetone) = 23.8 kcal/mol is in good agreement with the experimental value of the activation free energy ΔG(‡exp)270 K = 21.1 kcal/mol.

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The complexes of [( tBu PCP)IrH(Cl)] {1, tBu PCP = 1,3bis[(di-tert-butylphosphanyl)methyl]benzene} with pyridine (py, 2), 4-aminopyridine (4apy, 3) and 2-aminopyridine (2apy, 4) have been synthesized and fully characterized by variable-temperature spectroscopy (NMR, IR, and UV/Vis). In each case, the reaction yields a mixture of cis-and trans-hydrido-chlorido isomers. The stereochemistry of the latter was confirmed by single-crystal X-ray analysis of 2a and 3a, which showed that the pyridine ligands coordinated opposite the aryl ring do not produce an additional twist of the pincer ligand but lead to the elongation of all bonds involving the iridium atom. The chlorido ligand becomes substantially labilized owing to the strong trans effect of the hydrido ligand, and that in 3a it is prone to inter- [a] Complex 2b: 1 H NMR (300 MHz, CD 2 Cl 2 , 260 K): δ = 10.14 (pt, 2 J N,H = 4.5 Hz, 3 J H,H = 4.9 Hz, 1 H, o-Py), 7.89 (pt, 2 J N,H = 5.3 Hz, 3 J H,H = 4.5 Hz, 1 H, o-Py), 7.59 (t, 3 J H,H = 6.7 Hz, 1 H, p-Py), 7.22 (t, 3 J H,H = 6.1 Hz, 1 H, m-Py), 6.98 (t, 3 J H,H = 6.1 Hz, 1 H, m-Py), 6.88 (d, 3 J H,H = 7.3 Hz, 2 H, m-Ph), 6.72 (t, 3 J H,H = 7.3 Hz, 1 H, p-Ph), 2.94 (pq, 2 J P,H = 16.4 Hz, 4 H, CH 2 ), 1.25 (t, 2 J H,H = 6.3 Hz, 18 H, CH 3 ), 0.92 (t, 2 J H,H = 6.3 Hz, 18 H, CH 3 ), -21.64 (pq, 2 J N,H = 18.2 Hz, 2 J P,H = 15.5 Hz, 1 H, H) ppm. 31 P{ 1 H} NMR (121 MHz, CD 2 Cl 2 , 260 K): δ = 46.1 ppm. 15 N NMR (61 MHz, CD 2 Cl 2 , 260 K): δ = -138.7 ppm. ( tBu PCP)IrH(Cl)(4apy): Yield 87 %, ratio of isomers 1:2.5. C 29 H 50 ClP 2 N 2 Ir (716.35): calcd. C 48.62, H 7.04, N 3.91; found C 49.41, H 7.25, N 3.92.

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Bimetallic complexes [LW(CO)2(μ-CO)⋯Pd(PCP)] cooperatively activate amine-boranes for their dehydrogenation via N–H proton tunneling at RDS and H2 evolution from two neutral hydrides.