Acid–base chemistry of polypyridyl ruthenium compounds of (pyridin-2′-yl)-1,2,4-triazoles. X-Ray crystal structure of bis(2,2′-bipyridine)[3-methyl-5-(pyridin-2′-yl)-1,2,4-triazolato-N¹]ruthenium hexafluorophosphate tetrahydrate

Abstract

Pyridin-2'-yl)-l,2,4-triazoles. X-Ray Crystal Structure of Bis(2,2'-bipyridine)-[3-methyl-5-( pyridin-2'-yl)-I ,2,4-triazolato-N1] ruthenium

Experimental and theoretical studies of a triazole ligand and complexes formed with the lanthanides

“…In bis(2,2Ј-bipyridyl)-(3-methyl-5-pyridin-2-yl-1,2,4-triazole)ruthenium hexafluorophosphate tetrahydrate the Ru is bound to the N(2) triazole atom. 17 The authors suggest that this is the most favoured mode of co-ordination because of steric hindrance caused by the methyl group in the 5 position. Our own structural and molecular modelling studies suggest, however, that this steric hindrance is not a significant factor.…”

“…Ellipsoids at 30% probability. † The structure of the corresponding erbium complex was found to be isomorphous but the data were not of sufficient quality to report: a = 16.123 (17), b = 8.211 (11), c = 16.625(14) Å, β = 101.69(1)Њ, monoclinic, space group P2 1 /n, Z = 4.…”

Energy Transfer Pathways in Dinuclear Heteroleptic Polypyridyl Complexes: Through-Space vs Through-Bond Interaction Mechanisms

“…Upon protonation of the triazole ring, the ligand (H 2 mL/H 2 -pL) becomes a weaker σ-donor and a stronger π-acceptor, lowering the energy of the metal-based orbitals, which results in the observed blue shift in the absorption spectrum. 26,32 For the Os(II) complexes, additional absorption bands are observed at 600-660 nm, which can be assigned to formally forbidden triplet dπ-π* bpy MLCT transitions. 33 The absorption spectra of equimolar solutions of the heterodinuclear complexes mRuOs and pRuOs and 1:1 mixtures of the corresponding homodinuclear species, pRuRu/pOsOs and mRuRu/mOsOs, were found to be identical.…”

“…The values obtained for the individual compounds are given in the Supporting Information (Table S4). 26,34 It is notable that for the dinuclear species only one pK a value is obtained. 13 The absence of a ground state interaction between the two 1,2,4-triazole moieties demonstrates the weakness of the bridging phenyl group in mediating intercomponent interactions.…”

The Effective Electron‐Transfer Distance in Dinuclear Ruthenium Complexes Containing the Unsymmetrical Bridging Ligand 3,5‐Bis(2‐pyridyl)‐1,2,4‐triazolate

“…[19][20][21][22][23] Whereas Browne and co-workers [24] concluded that the stereoisomeric identity of the ∆Λ, Λ∆, ∆∆ and ΛΛ forms of [{Ru(bpy) 2 } 2 (µ-bpt -)] 3+ had no influence on the photophysical properties of the complexes either at 77 K or room temperature, the influence of stereochemical effects on the IVCT properties of the systems were not addressed. Previous studies have, however, reported the redox and spectroscopic characteristics, [9,11,12,[25][26][27] resonance Raman spectra [28] and photophysical behavior [9,29] of stereoisomeric mixtures of the homo-and hetero-dinuclear complexes of ruthenium, osmium, rhodium and iridium incorporating bpt -and its protonated analog, Hbpt. It must be noted that due to the inequivalence of the metal coordination sites, the ∆Λ/Λ∆ form comprises a pair of geometric isomers.…”