Dicarboxy bridge

An analysis of the EPR spectra of the P4 -L-Q ion radical pairs [41] made it possible to estimate the energy of magnetic dipole-dipole interaction between the paramagnetic fragments P+ and Q in these particles and to calculate from this energy the mean distance RPq 10-12 A between P and Q fragments in the molecule of the kind, depicted in Fig. 8 (n = 2), in which the dicarboxy bridge... 

Scheme 3 shows the details of the synthetic strategy adopted for the preparation of heteroleptic cis- and trans-complexes. Reaction of dichloro(p-cymene)ruthenium(II) dimer in ethanol solution at reflux temperature with 4,4,-dicarboxy-2.2 -bipyridine (L) resulted the pure mononuclear complex [Ru(cymene)ClL]Cl. In this step, the coordination of substituted bipyridine ligand to the ruthenium center takes place with cleavage of the doubly chloride-bridged structure of the dimeric starting material. The presence of three pyridine proton environments in the NMR spectrum is consistent with the symmetry seen in the solid-state crystal structure (Figure 24). 

Liu. Y. Li, L. Zhang, H.-Y. Zhao. Y.-L. Wu. X. Bis(pseudopolyrotaxane)s possessing copper (TI) ions formed by different polymer chains and bis(P-cyclodex-trinls bridged with a 2,2 -bipyridine-4,4 -dicarboxy tether. Maeromolecules 2002. 35, 9934-9938. 

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