%0 Generic
%A Singh, Priti
%A Fiedler, Jan
%A Záliš, Stanislav
%A Duboc, Carole
%A Niemeyer, Mark
%A Lissner, Falk
%A Schleid, Thomas
%A Kaim, Wolfgang
%D 2007
%T Spectroelectrochemistry and DFT Analysis of a New {RuNO}n Redox
System with Multifrequency EPR Suggesting Conformational Isomerism
in the {RuNO}7 State
%U https://acs.figshare.com/articles/dataset/Spectroelectrochemistry_and_DFT_Analysis_of_a_New_RuNO_i_sup_n_sup_i_sup_sup_Redox_System_with_Multifrequency_EPR_Suggesting_Conformational_Isomerism_in_the_RuNO_sup_7_sup_State/2978203
%R 10.1021/ic701206a.s007
%2 https://acs.figshare.com/ndownloader/files/4678747
%K Ru
%K bpym
%K g 2 components
%K OH
%K EPR spectroscopy
%K DFT calculations support
%K acetonitrile substitution product
%K UV
%K RuNO
%K n Redox System
%K CH
%K CN
%K Multifrequency EPR Suggesting Conformational Isomerism
%K II
%X The compound [Ru(NO)(bpym)(terpy)](PF6)3, bpym = 2,2‘-bipyrimidine and terpy = 2,2‘:6‘,2‘ ‘-terpyridine, with a
{RuNO}6 configuration (angle Ru−N−O 175.2(4)°) was obtained from the structurally characterized precursor [Ru(NO2)(bpym)(terpy)](PF6), which shows bpym-centered reduction and metal-centered oxidation, as evident from
EPR spectroscopy. The relatively labile [Ru(NO)(bpym)(terpy)]3+, which forms a structurally characterized acetonitrile
substitution product [Ru(CH3CN)(bpym)(terpy)](PF6)2 upon treatment with CH3OH/CH3CN, is electrochemically reduced
in three one-electron steps of which the third, leading to neutral [Ru(NO)(bpym)(terpy)], involves electrode adsorption.
The first-two reduction processes cause shifts of ν(NO) from 1957 via 1665 to 1388 cm-1, implying a predominantly
NO-centered electron addition. UV−vis-NIR Spectroscopy shows long-wavelength ligand-to-ligand charge transfer
absorptions for [RuII(NO-I)(bpym)(terpy)]+ in the visible region, whereas the paramagnetic intermediate [Ru(NO)(bpym)(terpy)]2+ exhibits no distinct absorption maximum above 309 nm. EPR spectroscopy of the latter at 9.5, 95,
and 190 GHz shows the typical invariant pattern of the {RuNO}7 configuration; however, the high-frequency
measurements at 4 and 10 K reveal a splitting of the g1 and g2 components, which is tentatively attributed to
conformers resulting from the bending of RuNO. DFT calculations support the assignments of oxidation states and
the general interpretation of the electronic structure.
%I ACS Publications