This paper presents synthesis and photophysical investigation of cyclometalated water-soluble Pt(II) and Ir(III) complexes containing auxiliary sulfonated diphosphine (bis(diphenylphosphino)benzene (dppb), P^P*) ligand. The complexes demonstrate considerable variations in excitation (extending up to 450 nm) and emission bands (with maxima ranging from ca. 450 to ca. 650 nm), as well as in the sensitivity of excited state lifetimes to molecular oxygen (from almost negligible to more than 4-fold increase in degassed solution). Moreover, all the complexes possess high two-photon absorption cross sections

The substituent effects on the potential energy surfaces of RBBiR (R = F, OH, H, CH3, SiH3, Tbt, Ar*, SiMe­(SitBu3)2, and SiiPrDis2) are determined using density functional theories (M06-2X/Def2-TZVP, B3PW91/Def2-TZVP, and B3LYP/LANL2DZ+dp). The theoretical results show that all of the triply bonded RBBiR molecules prefer to adopt a bent geometry (i.e., ∠RBBi ≈ 180° and ∠BBiR ≈ 90°), which agrees well with the valence-electron bonding model. It is also demonstrated that the smaller groups, such as R = H, F, OH, CH3, and SiH3, neither kinetically nor thermodynamically stabilize the triply bonded RBBiR compounds, except for H3SiBBiSiH3. However, triply bonded R′BBiR′ molecules that feature bulkier substituents (R′ = SiiPrDis2, SiMe­(SitBu3)2, Tbt, and Ar*) are predicted to have a thermodynamic and kinetic global minimum. This theoretical study finds that both the steric and the electronic effects of bulkier substituent groups play a significant role in forming triply bonded RBBiR species that are experimentally obtainable and isolable in a stable form.

The mechanisms for photochemical carboxylation reactions are studied theoretically using two model systems: o-methylbenzophenone and o-methylacetophenone, with the M06-L and the 6-311G(d,p) basis set.

The effect of substitution on the potential energy surfaces of RE 13 ≡BiR (E