Abstract:PPh2)2Rh(COD) should be half the number in [Rh(/t-PPh2)(COD)]2, if both COD ligands are lost from the latter. The rate of hydrogenation of 1-octene with [(DPPE)Rh(/u-PPh2)2Rh(COD)] is actually greater than the rate for [Rhgrants that aided the purchase of the 300-and 200-MHz NMR instruments, respectively. We also thank Professor G. G. Christoph for help with the X-ray structure determination and the John Simon Guggenheim Foundation for a fellowship to D.W.M. for 1981-1982.
“…It has been reported that in the methoxyl-bridged Cu 2 O 2 unit there is an antiferromagnetic interaction when the Cu-O-Cu angle is larger than 95.71 and a ferromagnetic interaction when the Cu-O-Cu angle is smaller than 95.71. 19,23,24 In complex 6, the methoxyl-bridged Cu1-O51-Cu2 and Cu1-O52-Cu2 angles are 98.5(2) and 98.3(2)1, respectively, suggesting the presence of an antiferromagnetic intra-dimer interaction. The plot of w M À1 vs. T is shown in Fig.…”
“…It has been reported that in the methoxyl-bridged Cu 2 O 2 unit there is an antiferromagnetic interaction when the Cu-O-Cu angle is larger than 95.71 and a ferromagnetic interaction when the Cu-O-Cu angle is smaller than 95.71. 19,23,24 In complex 6, the methoxyl-bridged Cu1-O51-Cu2 and Cu1-O52-Cu2 angles are 98.5(2) and 98.3(2)1, respectively, suggesting the presence of an antiferromagnetic intra-dimer interaction. The plot of w M À1 vs. T is shown in Fig.…”
“…A commonly used group of molecules for these purposes are nitrogen donor ligands. Aromatic pyridines and polypyridines [14][15][16][17] are typical examples of such molecules. Non-aromatic rings such as piperidine and piperazine have also been used for construction of extended copper halide structures.…”
“…Hydroxoand alkoxo-bridged Cu(II) complexes exhibit magnetic behaviour ranging from the antiferromagnetic to ferromagnetic depending on the geometry of Cu 2 (OR) n (n = 1 and 2, R = H, alkyl, aryl) binding units. [16][17][18][19][20][21][22][23][24][25][26][27][28] The well-studied hydration reaction of the di-pyridylketone (dpk) ligand has been implemented to construct several metal clusters, in which the two pyridyl N atoms and the gem-diol obtained from metal-promoted hydration act as four potential donor sites and the resulting M(II)-dpk-azide (M = Co, Ni) compounds have been characterized so far to be isomorphous. 14c, 29 Herein, an analogous hydration reaction would be expected using di-pyridylketone azine (dpka) (Scheme 1) for the assembly of metal clusters and the hydration or solvolysis reaction will occur at the imino group to widen the range of structural arrangements.…”
A series of metal complexes were achieved from the metal-assisted solvolysis reaction of di-pyridylketone azine (dpka). The tetranuclear nickel cluster , [Ni(2)[dpk(O)(OH)][dpk(O)(OCH(3))](N(3))(2)](2), is centrosymmetric with a central core described as an edge-shared triangle core. Neighboring Ni(II) ions are alternately bridged by (micro(2)-N(3), micro(3)-O) and (micro(2)-O, micro(3)-O) double bridges. Complex , [Cu(4)[dpk(O)(OCH(3))](4)(N(3))(2)](CuCl(2))(2) contains a tetranuclear cluster and two identical [CuCl(2)]M(-) anions. The tetranuclear structure has two crystallographically imposed twofold axes, in which the four copper ions are arranged to be rhombic shape. The neighboring copper(ii) ions along the lateral are bridged by single micro(2)-O from the ligand dpk(O)(OCH(3)) and the short diagonal copper ions are bridged by two symmetric end-on azides. In dinuclear Cu(ii) complex [Cu(2)[dpka(OCH(2)CH(3))]Cl(2)](ClO(4)) (3), the metal centers are coordinated in a planar configuration and bridged by a -N-N- bridge. It is also observed that the Cl atom coordinated to one Cu(II) center is also weakly coordinated to another inversion related Cu(II) to generate a centrosymmetric dimer. The metal centers in one-dimensional polymeric Cu(ii) complex [Cu(2)[dpka(OCH(3))](N(3))(2)(ClO(4))](n) (4), however, are bridged by a -N-N- bridge and an end-to-end azide bridge, alternately. Magnetic susceptibility measurements indicate that shows ferromagnetic interaction within the tetranuclear cluster, and that displays moderately strong antiferromagnetic interaction (J = -56.7 cm(-1)) for the bis(micro-N(3)) bridge. For compound , it shows strong antiferromagnetic coupling (J = -286 cm(-1)) between the intradinuclear Cu(II) ions mediated by the single N-N bridge and negligible magnetic interactions between the adjacent dinuclear Cu(II) ions mediated by the single end-to-end azide bridge. The mechanism of the metal-assisted solvolysis reaction was also discussed.
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