80939-25-9Relevant academic research and scientific papers
INFLUENCE OF HYDROGEN BONDING ON THE PROPERTIES OF IRON PORPHYRIN IMIDAZOLE COMPLEXES. AN INTERNALLY HYDROGEN BONDED IMIDAZOLE LIGAND.
Quinn,Mercer-Smith,Burstyn,Valentine
, p. 4136 - 4144 (2007/10/02)
Two new imidazole derivatives have been synthesized, cis-methyl urocanate and trans-methyl urocanate. The IR properties of these imidazole derivatives have been compared with those of imidazole itself and other imidazole derivatives. A series of complexes of the form Fe**I**I**I(TPP)(L)//2SbF//6, where TPP equals tetraphenylporphyrin and L equals imidazole or a substituted imidazole, have been synthesized and characterized by visible, electron paramagnetic resonance and IR spectroscopy and cyclic voltammetry in order to evaluate the effects of hydrogen bonding of coordinated imidazole ligands on the properties of iron porphyrin complexes.
New Five- and Six-Coordinate Imidazole and Imidazolate Complexes of Ferric Tetraphenylporphyrine
Quinn, Robert,Nappa, Mario,Valentine, Joan S.
, p. 2588 - 2595 (2007/10/02)
The synthesis of several new imidazole and imidazolate complexes of ferric tetraphenylporphyrine (TPP) are reported.The following coplexes have been made with L = imidazole (ImH) or 4-methylimidazole (4MeImH) and L- = imidazolate (Im-) or 4-methylimidazolate (4MeIm-): FeTPP(L)(L-), -2>-, and (SbF6).Addition of Im- to FeTPPCl resulted in the formation first of the imidazolate-bridged complex + and then of -.Similar addition of 4MeIm- to FeTPPCl resulted in the formation first of the high-spin mononuclear complex FeTPP(4MeIm) and then of -.The affinity of (SbF6) for a second 4MeImH was found to be very high, with K >/= 107 M-1 in toluene, 25 deg C.By contrast, 4MeImH was found preferentially to hydrogen bond to Fe(TPP)(4MeIm), with K ca. 5 * 104 M-1 in THF, 25 deg C.Coordination of 4MeImH was only observed at high concentration of ligand (K ca. 50 +/- 10 M-1).The monoimidazole complex (SbF6) was concluded to be high spin after a comparison of the visible spectral properties of a large number of ferric TPP complexes.
