Bridging ligands bridge index

The bridging index is the number of central atoms linked by a particular bridging ligand (see Section IR-9.2.5.2). Bridging can be through one atom or through a longer array of atoms. 

The bridging index n, the number of coordination centres connected by a bridging ligand, is placed as a right subscript. The bridging index 2 is not normally indicated. Multiple... 

The terminally substituted diphosphines have also been used to prepare Au complexes (16-18, Chart 5.4) [37]. The metal does not shift the absorption maxima much relative to the free ligands however, dual emission is observed in the case of 17. This is attributed to emission from both monomer and an Au-Au bridged dimer, which is observed in the solid state. Several of the Pt and Pd complexes (19-24, Chart 5.4) have also been characterized crystallographically and some of these structures show k-k stacking interactions between thiophene rings in the solid state [38]. A third-order nonlinear optical response was obtained for the Pd and Pt complexes (21 and 24) using Z-scan measurements [39]. These complexes have nonlinear refractive index values of (—1.5 to —1.8) Hicks and co-workers have prepared a... 

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