Binuclear planar molecules

Reaction of [Rh(/z-Cl)(CO)2]2 with sodium pyrazolate leads to 206 (85CJC699). The Rh2N2Cl ring has the envelope conformation. The rhodium atom has distorted square-planar coordination. The molecules in the crystalline lattice form onedimensional stacking units with alternating rhodium atoms in the binuclear units, intermolecularly interacting in a zigzag chain. 

A single-crystal X-ray analysis of the triphenylphosphine complex [Ni(PPh3)(CS2)]2 has revealed that the complex has the binuclear structure (1017). The complex [Ni(PMe3)2(CS2)2] displays NiPSCS coordination (1018) and is severely distorted from square planar. Of interest is the fact that the SC(S)SC(PMe3)S linkage can be formally described as a condensation product of two molecules of CS2 with one molecule of PMe3.2464... 

The potentially bridging ligand (45) was prepared in an attempt to form binuclear complexes involving thiolate bridging. Mononuclear bis chelates only were isolated with Cu" and Ni in either anhydrous or hydrated forms. The diamagnetic NiLj chelate is cis planar with weak bonding to the metal atom from O atoms of adjacent molecules. The structure of the Ni" chelate of a closely related ligand was reported also. ... 

Unlike with Pd complexes, when DTBNpP is mixed with Pt(PhCN)2Cl2 (1 1 mol per Pt atom) in CH2CI2 at 20° for a few minutes, a white binuclear complex is formed. It was characterised by spectroscopic and Xray diffraction methods to have the structure [PtCl(PBu 2CH2CMe2CH2)]2, i.e. one of the methyl groups of the neopentyl moiety is folded back and is metallated by the Pt to form a five membered Pt heterocyclic ring — and the molecule is dimeric. Such metallation does not occur with PBu 2Pr" under similar conditions, and in this case the monomeric cis and trans [PtCl2(PhCN)(PBu 2Pr")j square planar complexes are formed. [Mason et al. JCS Chem Commun 292 1976.]... 

Another noticeable example of an MOF constructed from a polytopic carboxylic acid and the binuclear metal-carboxylate paddlewheel-like cluster MBB, equivalent to a square planar SBU, is the one commonly referred to as HKUST-1 MOF, with the general formula [Cu3(TMA)2 (H20)3] where TMA denotes trimesic acid (1,3,5-benzene-tricarboxylic acid) (Figure 13, ). The MBB is defined by four carboxylate ions coordinating two Cu(II) ions in a paddlewheel-like structure with four points of extension defining a square-planar SBU. The authors reported the capability of exchanging the axial water molecules coordinated to the Cu(II) paddlewheel, postsynthetically, with pyridine molecules, opening the door for further investigations toward the viability of preferential sorption of small molecules and/or catalysis on coordinatively unsaturated metal centers. 

Numerous structures of alkoxo copper(ii) complexes have been determined. The tridentate diolate ligands [0(CH2)4N=C(Me)CH2C(CF3)20] and [0(CH2)3N=C(Me)CH2C(CF3)20] gave binuclear complexes [Cu2 m-0(CH2) N=C(Me)CH2C(CF3)20 2] (n = 4, 3). Each molecule has square planar Cu(ii) atoms with an essentially near planar 0NCu(/r-0)2CuN0 framework." " ... 

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