%0 Journal Article %1 Agarwala.2012b %A Agarwala, Hemlata %A Scherer, Thomas Michael %A Maji, Somnath %A Mondal, Tapan Kumar %A Mobin, Shaikh M. %A Fiedler, Jan %A Urbanos, Francisco A. %A Jimenez-Aparicio, Reyes %A Kaim, Wolfgang %A Lahiri, Goutam Kumar. %D 2012 %J Chemistry - A European Journal %K acac bridged crystal cyclic dinuclear dinuclear;ruthenium electronic mixed oxamidato prepn ruthenium structure structure;spectroelectrochem valent voltammetry %N 18 %P 5667-5675, S5667/1-S5667/21 %R 10.1002/chem.201103618 %T Correspondence of RuIIIRuII and RuIVRuIII Mixed Valent States in a Small Dinuclear Complex %V 18 %X The diruthenium(III) compd. (m-oxa)Ru(acac)22 1, oxa2- = oxamidato(2-), acac- = 2,4-pentanedionato exhibits an S = 1 ground state with antiferromagnetic spin-spin coupling (J = -40 cm-1). The mol. structure in the crystal of 1·2C7H8 revealed an intramol. metal-metal distance of 5.433 \AA and a notable asymmetry within the bridging ligand. Cyclic voltammetry and spectroelectrochem. (EPR, UV/visible/NIR) of the two-step redn. and of the two-step oxidn. (irreversible 2nd step) produced monocation and monoanion intermediates (Kc = 105.9) with broad NIR absorption bands (e $\sim$2000 -1 cm-1) and maxima at 1800 (1-) and 1500 nm (1+). TD-DFT calcns. support a RuIIIRuII formulation for 1- with a doublet ground state. The 1+ ion (RuIVRuIII) was calcd. with an S = 3/2 ground state and the doublet state higher in energy (DE = 694.6 cm-1). The Mulliken spin d. calcns. showed little participation of the ligand bridge in the spin accommodation for all paramagnetic species (m-oxa)Ru(acac)22n, n = +1, 0, -1, and, accordingly, the NIR absorptions were identified as metal-to-metal (intervalence) charge transfers. Whereas only one such NIR band was obsd. for the RuIIIRuII (4d5/4d6) system 1-, the RuIVRuIII (4d4/4d5) form 1+ exhibited extended absorbance over the UV/visible/NIR range. on SciFinder(R)

@article{Agarwala.2012b, abstract = {The diruthenium(III) compd. [(\textgreek{m}-oxa){Ru(acac)2}2] [1, oxa2- = oxamidato(2-), acac- = 2,4-pentanedionato] exhibits an S = 1 ground state with antiferromagnetic spin-spin coupling (J = -40 cm-1). The mol. structure in the crystal of 1·2C7H8 revealed an intramol. metal-metal distance of 5.433 {\AA} and a notable asymmetry within the bridging ligand. Cyclic voltammetry and spectroelectrochem. (EPR, UV/visible/NIR) of the two-step redn. and of the two-step oxidn. (irreversible 2nd step) produced monocation and monoanion intermediates (Kc = 105.9) with broad NIR absorption bands (\textgreek{e} $\sim$2000 -1 cm-1) and maxima at 1800 (1-) and 1500 nm (1+). TD-DFT calcns. support a RuIIIRuII formulation for 1- with a doublet ground state. The 1+ ion (RuIVRuIII) was calcd. with an S = 3/2 ground state and the doublet state higher in energy (\textgreek{D}E = 694.6 cm-1). The Mulliken spin d. calcns. showed little participation of the ligand bridge in the spin accommodation for all paramagnetic species [(\textgreek{m}-oxa){Ru(acac)2}2]n, n = +1, 0, -1, and, accordingly, the NIR absorptions were identified as metal-to-metal (intervalence) charge transfers. Whereas only one such NIR band was obsd. for the RuIIIRuII (4d5/4d6) system 1-, the RuIVRuIII (4d4/4d5) form 1+ exhibited extended absorbance over the UV/visible/NIR range. [on SciFinder(R)]}, added-at = {2019-07-15T13:41:23.000+0200}, author = {Agarwala, Hemlata and Scherer, Thomas Michael and Maji, Somnath and Mondal, Tapan Kumar and Mobin, Shaikh M. and Fiedler, Jan and Urbanos, Francisco A. and Jimenez-Aparicio, Reyes and Kaim, Wolfgang and Lahiri, Goutam Kumar.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/22da67271dafd3b07a984aec21ddb3721/b_schwederski}, doi = {10.1002/chem.201103618}, interhash = {e0d6af10b3f84f6f9f062b39865a8a32}, intrahash = {2da67271dafd3b07a984aec21ddb3721}, issn = {0947-6539}, journal = {Chemistry - A European Journal}, keywords = {acac bridged crystal cyclic dinuclear dinuclear;ruthenium electronic mixed oxamidato prepn ruthenium structure structure;spectroelectrochem valent voltammetry}, number = 18, pages = {5667-5675, S5667/1-S5667/21}, timestamp = {2019-07-15T11:42:10.000+0200}, title = {Correspondence of RuIIIRuII and RuIVRuIII Mixed Valent States in a Small Dinuclear Complex}, volume = 18, year = 2012 }