The Cu(I)-catalyzed 1,3-cycloaddition of organic azides with terminal alkynes, the CuAAC "click" reaction is currently receiving considerable attention as a mild, modular method for the generation of functionalized ligand scaffolds. Herein we show that mild one-pot "click" methods can be used to readily and rapidly synthesize a family of functionalized bidentate 2-pyridyl-1,2,3-triazole ligands, containing electrochemically, photochemically, and biologically active functional groups in good to excellent yields (47-94%). The new ligands have been fully characterized by elemental analysis, HR-ESI-MS, IR, (1)H and (13)C NMR and in three cases by X-ray crystallography. Furthermore we have demonstrated that this family of functionalized "click" ligands readily form bis-bidentate Pd(II) complexes. Solution studies, X-ray crystallography, and density functional theory (DFT) calculations indicate that the Pd(II) complexes formed with the 2-(1-R-1H-1,2,3-triazol-4-yl)pyridine series of ligands are more stable than those formed with the [4-R-1H-1,2,3-triazol-1-yl)methyl]pyridine "click" ligands.

Officer, D. L. (2009). A spectroscopic and DFT study of thiophene-substituted metalloporphyrins as dye-sensitized solar cell dyes. Physical Chemistry Chemical Physics, 11 (27),[5598][5599][5600][5601][5602][5603][5604][5605][5606][5607] A spectroscopic and DFT study of thiophene-substituted metalloporphyrins as dye-sensitized solar cell dyes Abstract A combination of density functional theory calculations, electronic absorption and resonance Raman spectroscopy has been applied to a series of beta-substituted zinc porphyrins to elucidate how the substituent affects the electronic structure of the metalloporphyrin and assign the nature of electronic transitions in the visible region. The use of conjugated beta substituents invokes a large perturbation to both the nature and energy of the frontier molecular orbitals and results in the generation of additional molecular orbitals from the parent metalloporphyrin species. A complicated electronic absorption spectra is observed which can be rationalised by an extension of Goutermans' four-orbital model. The excitations involved in the visible transitions have been determined using resonance Raman spectroscopy. This has revealed that the B band retains much of its original nature and is centred largely on the porphyrin core. Additional electronic transitions invoke population of orbitals localised on the substituent chain. The nature of the electronic transitions depends heavily on the type of b substituent. The results of this investigation question some previously held beliefs for the rational design of metalloporphyrins for dye-sensitized solar cell applications. A combination of density functional theory calculations, electronic absorption and resonance Raman spectroscopy has been applied to a series of b-substituted zinc porphyrins to elucidate how the substituent affects the electronic structure of the metalloporphyrin and assign the nature of electronic transitions in the visible region. The use of conjugated b substituents invokes a large perturbation to both the nature and energy of the frontier molecular orbitals and results in the generation of additional molecular orbitals from the parent metalloporphyrin species. A complicated electronic absorption spectra is observed which can be rationalised by an extension of Goutermans' four-orbital model. The excitations involved in the visible transitions have been determined using resonance Raman spectroscopy. This has revealed that the B band retains much of its original nature and is centred largely on the porphyrin core. Additional electronic transitions invoke population of orbitals localised on the substituent chain. The nature of the electronic transitions depends heavily on the type of b substituent. The results of this investigation question some previously held beliefs for the rational design of metalloporphyrins for dye-sensitized solar cell applications.

A one-pot synthesis of 2,6-dibromodithieno[3,2-b;2',3'-d]thiophene (dibromo-DTT, 4) was developed. A key step was bromodecarboxylation of DTT-2,6-dicarboxylic acid, obtained by saponification of the diester 1. The donor-acceptor dye DAHTDTT (13), based on a central 2,6-bis[2'-(3'-hexylthienyl)]dithieno[3,2-b;2',3'-d]thiophene core (9), was prepared and incorporated in a dye-sensitized solar cell (DSC), which exhibited an energy conversion efficiency of 7.3% with V(oc) of 697 mV, J(sc) of 14.4 mA/cm(2), and ff of 0.73 at 1 sun.