Molecular Engineering of Photosensitizers for Nanocrystalline Solar Cells:  Synthesis and Characterization of Ru Dyes Based on Phosphonated Terpyridines

Abstract

We report the results of an investigation on the preparation, spectral, and photoelectrochemical properties of Ru(II)-polypyridyl complexes containing a new phosphonated terpyridine (P-terpy) ligand: [Ru(H(2)P-terpy)(2)] and [Ru(HP-terpy)(Me(2)bpy)(NCS)]. Resonance Raman spectral and luminescence studies allow probing into the nature of the low-energy MLCT transitions observed in these complexes. The crystal and molecular structure of the mixed-ligand complex [Ru(HP-terpy)(Me(2)bpy)(NCS)] based on X-ray diffraction study is reported. This complex appears to be a promising candidate as a photosensitizer in dye-sensitized photoelectrochemical cells based on nanocrystalline films of TiO(2).

Sticking and patching: tuning and anchoring cyclometallated ruthenium(ii) complexes

“…18,35,36 The ester H7 and carboxylic acid H 2 8 (Scheme 2) were prepared according to literature methods, and their spectroscopic signatures were in accord with those reported. 28 The introduction of phenyl spacers between metal-binding and anchoring domains is beneficial in both n-and p-type dyes, 14,36 and ligand H9 was designed with this in mind.…”

To deprotect or not to deprotect: Phosphonate ester versus phosphonic acid anchor ligands in copper(I)-based dye-sensitized solar cells

“…The most efficient method is reaction of 2 with aqueous HCl (6 M) at reflux for 2 days, followed by treatment of the residue with aqueous acetic acid at reflux. 2,2':6',2''-Terpyridine-4'-phosphonic acid ((4'-(HO) 2 OPtpy) and 2,2'-bipyridine-4,4'-diphosphonic acid have been used as anchoring ligands in n-type dyes incorporating {Ru(tpy) 2 } 2+ , {Ru(tpy)(N^N)X} n+ or {Ru(bpy) 2 X 2 } n+ (N^N = diimine, X -= NCS -, Cl -or CN -) chromophores [14,15,16]. These phosphonic acids are prepared by hydrolytic deprotection of the ruthenium-bound diethyl phosphonates, but reaction may not proceed to completion, terminating at the corresponding monoester, depending on reaction conditions [14,15,17,18].…”

“…2,2':6',2''-Terpyridine-4'-phosphonic acid ((4'-(HO) 2 OPtpy) and 2,2'-bipyridine-4,4'-diphosphonic acid have been used as anchoring ligands in n-type dyes incorporating {Ru(tpy) 2 } 2+ , {Ru(tpy)(N^N)X} n+ or {Ru(bpy) 2 X 2 } n+ (N^N = diimine, X -= NCS -, Cl -or CN -) chromophores [14,15,16]. These phosphonic acids are prepared by hydrolytic deprotection of the ruthenium-bound diethyl phosphonates, but reaction may not proceed to completion, terminating at the corresponding monoester, depending on reaction conditions [14,15,17,18]. Partial hydrolysis of diester ligands can also occur during complexation of the ester-functionalized ligands with ruthenium(II) [16,19].…”

Microwave-assisted Hirao reaction: recent developments

“…Arylphosphonate scaffolds are used in designing fuel cell membranes [39] and materials with special optical properties [41][42][43]. Arylphosphonates are the phosphonic acids precursors, which can be used for their water-soluble properties and for the synthesis of mixed organic-inorganic materials [44,45].…”