TY - JOUR
T1 - The effects of N-heterocyclic ligands on the nature of the Ru-(NO) bond in ruthenium tetraammine nitrosyl complexes
AU - Caramori, Giovanni F.
AU - Frenking, Gernot
PY - 2009/6
Y1 - 2009/6
N2 - Quantum chemical calculations at the DFT level have been carried out to analyze quantitatively the RuII-(NO) +, Ru III-(NO) 0 and RuII-(NO) 0 bonds in trans-[RuII (NH3)4 (L)(NO)] q and trans-[RuII (NH3)4 (L)(NO)] q-1 complexes, where L = 4-picoline (4-pic), C-bound imidazole (imC), N-bound imidazole (imN), nicotinamide (nic), pyridine (py), and pyrazine (pz). Equilibrium geometries and the vibrational frequencies are reported for the ground state GS and light-induced metastable states, MS1 and MS2, presenting good agreement with the experimental data. The nature of the Ru II-(NO) + and RuII- (NO) 0 bonds was investigated by means of the energy decomposition analysis, EDA. The Ru-(NO) bonding situation has been analyzed in two different situations: prior and after one-electron reduction at the NO+ group. The EDA results for the complexes prior to the reduction of the NO+ indicate that the metalligand π-orbital interactions between NO+ and the [Ru II (NH3)4 (L)] q-1 are the most important term and that the trans-ligands imN and nic contribute to an increase in the π-donor strength of the metal centre towards NO+. For RuIII-(NO)0 bonds, the smallest values of ΔE int, ΔEPauli, ΔEelstat, and D e are observed when L = imC or L = nic, independent of the state under consideration, GS or MS1, indicating that when L = imC or nic the Ru III-(NO) 0 bond in GS or in MS1 states is more labile. After the reduction of the NO+ group, the RuII-(NO) 0 becomes more labile when the trans-ligand is imC, which agrees with the experimental rate constants of NO0 dissociation.
AB - Quantum chemical calculations at the DFT level have been carried out to analyze quantitatively the RuII-(NO) +, Ru III-(NO) 0 and RuII-(NO) 0 bonds in trans-[RuII (NH3)4 (L)(NO)] q and trans-[RuII (NH3)4 (L)(NO)] q-1 complexes, where L = 4-picoline (4-pic), C-bound imidazole (imC), N-bound imidazole (imN), nicotinamide (nic), pyridine (py), and pyrazine (pz). Equilibrium geometries and the vibrational frequencies are reported for the ground state GS and light-induced metastable states, MS1 and MS2, presenting good agreement with the experimental data. The nature of the Ru II-(NO) + and RuII- (NO) 0 bonds was investigated by means of the energy decomposition analysis, EDA. The Ru-(NO) bonding situation has been analyzed in two different situations: prior and after one-electron reduction at the NO+ group. The EDA results for the complexes prior to the reduction of the NO+ indicate that the metalligand π-orbital interactions between NO+ and the [Ru II (NH3)4 (L)] q-1 are the most important term and that the trans-ligands imN and nic contribute to an increase in the π-donor strength of the metal centre towards NO+. For RuIII-(NO)0 bonds, the smallest values of ΔE int, ΔEPauli, ΔEelstat, and D e are observed when L = imC or L = nic, independent of the state under consideration, GS or MS1, indicating that when L = imC or nic the Ru III-(NO) 0 bond in GS or in MS1 states is more labile. After the reduction of the NO+ group, the RuII-(NO) 0 becomes more labile when the trans-ligand is imC, which agrees with the experimental rate constants of NO0 dissociation.
KW - Energy decomposition analysis
KW - N-heterocyclic ligands
KW - Nitric oxide
KW - Ruthenium tetraammines
UR - http://www.scopus.com/inward/record.url?scp=68049127699&partnerID=8YFLogxK
M3 - 文章
AN - SCOPUS:68049127699
SN - 0011-1643
VL - 82
SP - 219
EP - 232
JO - Croatica Chemica Acta
JF - Croatica Chemica Acta
IS - 1
ER -