Electron transfer reactions of (C5R5)2(CO)2Ti (R = H or Me) with TCNE or TCNQ spectroelectrochemical assignment of metal and ligand oxidation states in [(C5Me5)2(CO)Ti(TCNX)]2-/-/o/+
The TCNX ligands TCNE (tetracyanoethene) and TCNQ (7,7,8,8-tetracyano-p-quinodimethane) react instantaneously with (C5R5)2(CO)2Ti, R = H or Me, to yield highly air-sensitive mononuclear complexes (C5R5)2(CO)Ti(TCNX) of which the sol. species (R = Me) were characterized also in the oxidized and reduced forms through cyclic voltammetry, EPR, IR and UV-visible spectroelectrochem. While oxidn. at rather low potentials yields labile carbonyltitanium(IV) species of the TCNX.bul.- ligands, the redn. occurs stepwise at unusually neg. potentials, first on the ligand (to yield coordinated TCNX2-) and then on the metal (to form TiII). For the neutral complexes (C5R5)2(CO)Ti2+q(TCNX-q) the results support a rather large amt. of charge transfer 1 \textless q \textless 2 from the metal to the acceptors TCNX. Evidence for the previously formulated (μ-TCNE2-)[(C5H5)2TiIV(CO)]2(TCNE2-) could not be found. (C5R5)2(CO)Ti(TCNE) are compared with related compds. (C5R5)2BrV(TCNE), (C6R6)(CO)2Cr(TCNE) and (C5R5)(CO)2Mn(TCNE). [on SciFinder(R)]
%0 Journal Article
%1 Hartmann.2003b
%A Hartmann, Heiko
%A Sarkar, Biprajit
%A Kaim, Wolfgang
%A Fiedler, Jan.
%D 2003
%J Journal of Organometallic Chemistry
%K EPR carbonyl complex cyclopentadienyl electrochem electron redox tetracyanoethene tetracyanoquinodimethane titanium;IR titanium;titanium transfer
%N 1
%P 100--107
%R 10.1016/j.jorganchem.2003.07.014
%T Electron transfer reactions of (C5R5)2(CO)2Ti (R = H or Me) with TCNE or TCNQ spectroelectrochemical assignment of metal and ligand oxidation states in [(C5Me5)2(CO)Ti(TCNX)]2-/-/o/+
%V 687
%X The TCNX ligands TCNE (tetracyanoethene) and TCNQ (7,7,8,8-tetracyano-p-quinodimethane) react instantaneously with (C5R5)2(CO)2Ti, R = H or Me, to yield highly air-sensitive mononuclear complexes (C5R5)2(CO)Ti(TCNX) of which the sol. species (R = Me) were characterized also in the oxidized and reduced forms through cyclic voltammetry, EPR, IR and UV-visible spectroelectrochem. While oxidn. at rather low potentials yields labile carbonyltitanium(IV) species of the TCNX.bul.- ligands, the redn. occurs stepwise at unusually neg. potentials, first on the ligand (to yield coordinated TCNX2-) and then on the metal (to form TiII). For the neutral complexes (C5R5)2(CO)Ti2+q(TCNX-q) the results support a rather large amt. of charge transfer 1 \textless q \textless 2 from the metal to the acceptors TCNX. Evidence for the previously formulated (μ-TCNE2-)[(C5H5)2TiIV(CO)]2(TCNE2-) could not be found. (C5R5)2(CO)Ti(TCNE) are compared with related compds. (C5R5)2BrV(TCNE), (C6R6)(CO)2Cr(TCNE) and (C5R5)(CO)2Mn(TCNE). [on SciFinder(R)]
@article{Hartmann.2003b,
abstract = {The TCNX ligands TCNE (tetracyanoethene) and TCNQ (7,7,8,8-tetracyano-p-quinodimethane) react instantaneously with (C5R5)2(CO)2Ti, R = H or Me, to yield highly air-sensitive mononuclear complexes (C5R5)2(CO)Ti(TCNX) of which the sol. species (R = Me) were characterized also in the oxidized and reduced forms through cyclic voltammetry, EPR, IR and UV-visible spectroelectrochem. While oxidn. at rather low potentials yields labile carbonyltitanium(IV) species of the TCNX.bul.- ligands, the redn. occurs stepwise at unusually neg. potentials, first on the ligand (to yield coordinated TCNX2-) and then on the metal (to form TiII). For the neutral complexes (C5R5)2(CO)Ti2+q(TCNX-q) the results support a rather large amt. of charge transfer 1 {\textless} q {\textless} 2 from the metal to the acceptors TCNX. Evidence for the previously formulated {(μ-TCNE2-)[(C5H5)2TiIV(CO)]2}(TCNE2-) could not be found. (C5R5)2(CO)Ti(TCNE) are compared with related compds. (C5R5)2BrV(TCNE), (C6R6)(CO)2Cr(TCNE) and (C5R5)(CO)2Mn(TCNE). [on SciFinder(R)]},
added-at = {2019-07-15T13:41:23.000+0200},
author = {Hartmann, Heiko and Sarkar, Biprajit and Kaim, Wolfgang and Fiedler, Jan.},
biburl = {https://puma.ub.uni-stuttgart.de/bibtex/27c4368c17e39616b6c89ea8ec04eca5c/b_schwederski},
doi = {10.1016/j.jorganchem.2003.07.014},
interhash = {efc373401d526957970aabdba2c1de25},
intrahash = {7c4368c17e39616b6c89ea8ec04eca5c},
journal = {Journal of Organometallic Chemistry},
keywords = {EPR carbonyl complex cyclopentadienyl electrochem electron redox tetracyanoethene tetracyanoquinodimethane titanium;IR titanium;titanium transfer},
number = 1,
pages = {100--107},
timestamp = {2019-07-15T11:42:10.000+0200},
title = {Electron transfer reactions of (C5R5)2(CO)2Ti (R = H or Me) with TCNE or TCNQ spectroelectrochemical assignment of metal and ligand oxidation states in [(C5Me5)2(CO)Ti(TCNX)]2-/-/o/+},
volume = 687,
year = 2003
}
