Formation, reactivity, and photorelease of metal bound nitrosyl in Ru(trpy)(L)(NO)n+ (trpy = 2,2':6',2''-terpyridine, L = 2-phenylimidazo4,5-f1,10-phenanthroline)
Nitrosyl complexes with Ru-NO6 and Ru-NO7 configurations were isolated in the framework of Ru(trpy)(L)(NO)n+ trpy = 2,2':6',2''-terpyridine, L = 2-phenylimidazo4,5-f1,10-phenanthroline as the perchlorate salts 4(ClO4)3 and 4(ClO4)2, resp. Single crystals of protonated material 4-H+(ClO4)4·2H2O reveal a Ru-N-O bond angle of 176.1(7)° and triply bonded N-O with a 1.127(9) \AA bond length. Structures were also detd. for precursor compds. of 43+ as Ru(trpy)(L)(Cl)(ClO4)·4.5H2O and Ru(trpy)(L-H)(CH3CN)(ClO4)3·H2O. In agreement with largely NO centered redn., a sizable shift in n(NO) frequency was obsd. on moving from 43+ (1953 cm-1) to 42+ (1654 cm-1). The RuII-NO.bul. in isolated or electrogenerated 42+ exhibits an EPR spectrum with g1 = 2.020, g2 = 1.995, and g3 = 1.884 in CH3CN at 110 K, reflecting partial metal contribution to the singly occupied MO (SOMO); 14N (NO) hyperfine splitting (A2 = 30 G) was also obsd. The plot of n(NO) vs. E°(RuNO6 $\rightarrow$ RuNO7) for 12 analogous complexes Ru(trpy)(L')(NO)n+ exhibits a linear trend. The electrophilic Ru-NO+ species 43+ is transformed to the corresponding Ru-NO2- system in the presence of OH- with k = 2.02 $\times$ 10-4 s-1 at 303 K. In the presence of a steady flow of dioxygen gas, the RuII-NO.bul. state in 42+ oxidizes to 43+ through an associatively activated pathway (DSdpl = -190.4 J K-1 M-1) with a rate const. (k s-1) of 5.33 $\times$ 10-3. On irradn. with light (Xe lamp), the acetonitrile soln. of paramagnetic Ru(trpy)(L)(NO)2+ (42+) undergoes facile photorelease of NO (kNO = 2.0 $\times$ 10-1 min-1 and t1/2 $\approx$ 3.5 min) with the concomitant formation of the solvate RuII(trpy)(L)(CH3CN)2+ 2'2+. The photoreleased NO can be trapped as an Mb-NO adduct. on SciFinder(R)
%0 Journal Article
%1 Maji.2008
%A Maji, Somnath
%A Sarkar, Biprajit
%A Patra, Malay
%A Das, Atanu Kumar
%A Mobin, Shaikh M.
%A Kaim, Wolfgang
%A Lahiri, Goutam Kumar.
%D 2008
%J Inorganic Chemistry
%K complex complex;kinetics complex;nitrosyl complex;ruthenium crystal electrochem nitrosyl oxidn phenylimidazophenanthroline photorelease prepn reactivity ruthenium structure terpyridine
%N 8
%P 3218--3227
%R 10.1021/ic702160w
%T Formation, reactivity, and photorelease of metal bound nitrosyl in Ru(trpy)(L)(NO)n+ (trpy = 2,2':6',2''-terpyridine, L = 2-phenylimidazo4,5-f1,10-phenanthroline)
%V 47
%X Nitrosyl complexes with Ru-NO6 and Ru-NO7 configurations were isolated in the framework of Ru(trpy)(L)(NO)n+ trpy = 2,2':6',2''-terpyridine, L = 2-phenylimidazo4,5-f1,10-phenanthroline as the perchlorate salts 4(ClO4)3 and 4(ClO4)2, resp. Single crystals of protonated material 4-H+(ClO4)4·2H2O reveal a Ru-N-O bond angle of 176.1(7)° and triply bonded N-O with a 1.127(9) \AA bond length. Structures were also detd. for precursor compds. of 43+ as Ru(trpy)(L)(Cl)(ClO4)·4.5H2O and Ru(trpy)(L-H)(CH3CN)(ClO4)3·H2O. In agreement with largely NO centered redn., a sizable shift in n(NO) frequency was obsd. on moving from 43+ (1953 cm-1) to 42+ (1654 cm-1). The RuII-NO.bul. in isolated or electrogenerated 42+ exhibits an EPR spectrum with g1 = 2.020, g2 = 1.995, and g3 = 1.884 in CH3CN at 110 K, reflecting partial metal contribution to the singly occupied MO (SOMO); 14N (NO) hyperfine splitting (A2 = 30 G) was also obsd. The plot of n(NO) vs. E°(RuNO6 $\rightarrow$ RuNO7) for 12 analogous complexes Ru(trpy)(L')(NO)n+ exhibits a linear trend. The electrophilic Ru-NO+ species 43+ is transformed to the corresponding Ru-NO2- system in the presence of OH- with k = 2.02 $\times$ 10-4 s-1 at 303 K. In the presence of a steady flow of dioxygen gas, the RuII-NO.bul. state in 42+ oxidizes to 43+ through an associatively activated pathway (DSdpl = -190.4 J K-1 M-1) with a rate const. (k s-1) of 5.33 $\times$ 10-3. On irradn. with light (Xe lamp), the acetonitrile soln. of paramagnetic Ru(trpy)(L)(NO)2+ (42+) undergoes facile photorelease of NO (kNO = 2.0 $\times$ 10-1 min-1 and t1/2 $\approx$ 3.5 min) with the concomitant formation of the solvate RuII(trpy)(L)(CH3CN)2+ 2'2+. The photoreleased NO can be trapped as an Mb-NO adduct. on SciFinder(R)
@article{Maji.2008,
abstract = {Nitrosyl complexes with {Ru-NO}6 and {Ru-NO}7 configurations were isolated in the framework of [Ru(trpy)(L)(NO)]n+ [trpy = 2,2':6',2''-terpyridine, L = 2-phenylimidazo[4,5-f]1,10-phenanthroline] as the perchlorate salts [4](ClO4)3 and [4](ClO4)2, resp. Single crystals of protonated material [4-H+](ClO4)4·2H2O reveal a Ru-N-O bond angle of 176.1(7)° and triply bonded N-O with a 1.127(9) {\AA} bond length. Structures were also detd. for precursor compds. of [4]3+ as [Ru(trpy)(L)(Cl)](ClO4)·4.5H2O and [Ru(trpy)(L-H)(CH3CN)](ClO4)3·H2O. In agreement with largely NO centered redn., a sizable shift in \textgreek{n}(NO) frequency was obsd. on moving from [4]3+ (1953 cm-1) to [4]2+ (1654 cm-1). The RuII-NO.bul. in isolated or electrogenerated [4]2+ exhibits an EPR spectrum with g1 = 2.020, g2 = 1.995, and g3 = 1.884 in CH3CN at 110 K, reflecting partial metal contribution to the singly occupied MO (SOMO); 14N (NO) hyperfine splitting (A2 = 30 G) was also obsd. The plot of \textgreek{n}(NO) vs. E°({RuNO}6 $\rightarrow$ {RuNO}7) for 12 analogous complexes [Ru(trpy)(L')(NO)]n+ exhibits a linear trend. The electrophilic Ru-NO+ species [4]3+ is transformed to the corresponding Ru-NO2- system in the presence of OH- with k = 2.02 $\times$ 10-4 s-1 at 303 K. In the presence of a steady flow of dioxygen gas, the RuII-NO.bul. state in [4]2+ oxidizes to [4]3+ through an associatively activated pathway (\textgreek{D}Sdpl = -190.4 J K-1 M-1) with a rate const. (k [s-1]) of 5.33 $\times$ 10-3. On irradn. with light (Xe lamp), the acetonitrile soln. of paramagnetic [Ru(trpy)(L)(NO)]2+ ([4]2+) undergoes facile photorelease of NO (kNO = 2.0 $\times$ 10-1 min-1 and t1/2 $\approx$ 3.5 min) with the concomitant formation of the solvate [RuII(trpy)(L)(CH3CN)]2+ [2']2+. The photoreleased NO can be trapped as an Mb-NO adduct. [on SciFinder(R)]},
added-at = {2019-07-15T13:41:23.000+0200},
author = {Maji, Somnath and Sarkar, Biprajit and Patra, Malay and Das, Atanu Kumar and Mobin, Shaikh M. and Kaim, Wolfgang and Lahiri, Goutam Kumar.},
biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2f1afab70796455c81ab743d474e2dfdd/b_schwederski},
doi = {10.1021/ic702160w},
interhash = {d3a66673bc049431ec582b8831f0259a},
intrahash = {f1afab70796455c81ab743d474e2dfdd},
issn = {0020-1669},
journal = {Inorganic Chemistry},
keywords = {complex complex;kinetics complex;nitrosyl complex;ruthenium crystal electrochem nitrosyl oxidn phenylimidazophenanthroline photorelease prepn reactivity ruthenium structure terpyridine},
number = 8,
pages = {3218--3227},
timestamp = {2019-07-15T11:42:10.000+0200},
title = {Formation, reactivity, and photorelease of metal bound nitrosyl in [Ru(trpy)(L)(NO)]n+ (trpy = 2,2':6',2''-terpyridine, L = 2-phenylimidazo[4,5-f]1,10-phenanthroline)},
volume = 47,
year = 2008
}