MODEL INVESTIGATIONS FOR VANADIUM-PROTEIN INTERACTIONS - SYNTHETIC, STRUCTURAL, AND PHYSICAL STUDIES OF VANADIUM(III) AND OXOVANADIUM(IV V)COMPLEXES WITH AMIDATE LIGANDS/
Ad. Keramidas et al., MODEL INVESTIGATIONS FOR VANADIUM-PROTEIN INTERACTIONS - SYNTHETIC, STRUCTURAL, AND PHYSICAL STUDIES OF VANADIUM(III) AND OXOVANADIUM(IV V)COMPLEXES WITH AMIDATE LIGANDS/, Inorganic chemistry, 35(2), 1996, pp. 357-367
Reaction of the amide ligand ridylmethylene)amino)phenyl]pyridine-2-ca
rboxamide (Hcapca) with VCl3 affords the compound trans-[VCl2(capca)]
(1), the first example of a vanadium(III) complex containing a vanadiu
m-deprotonated amide nitrogen bond, while reaction of bis(pentane-2,4-
dionato)oxovanadium(IV) with the related ligands N-[2-((2-phenolylmeth
ylene)amino)phenyl] pyridine-2-carboxamide (H(2)phepca), (2-hydroxyben
zamido)-2-(2-pyridinecarboxamido)benz (H(3)hypyb), and 1,2-bis(2-hydro
xybenzamido)benzene (H(4)hybeb) yields the complexes [VO(phepca)] (2),
Na[VO(hypyb)]. 2CH(3)OH (4 . 2CH(3)OH), and Na-2[VO(hybeb)]. 3CH(3)OH
(5 . 3CH(3)OH) respectively. The preparation of the complex -[2-((2-t
hiophenoylmethylene)amino)phenyl]pyridine 2-carboxamido}oxovanadium(IV
) (3) has been achieved by reaction of N-(2-aminophenyl)pyridine-2-car
boxamide and 2-mercaptobenzaldehyde with [VO(CH3COO)(2)](x). Oxidation
of complex 5 . 3CH(3)OH with silver nitrate gives its vanadium(V) ana
logue (8 . CH3OH), which is readily converted to its corresponding tet
raethylammonium salt. (10 . CH2Cl2) by a reaction with Et(4)NCl. The c
rystal structures of the octahedral 1 . CH3CN, and the square-pyramida
l complexes 3, 4 . CH3CN, 5 . 2CH(3)OH, and 10 were demonstrated by X-
ray diffraction analysis. Crystal data are as follows: 1 . CH3CN, C18H
13Cl2N4OV . CH3CN M(r) = 464.23, monoclinic, P2(1)/n, a = 10.5991(7) A
ngstrom, b = 13.9981(7) Angstrom, c = 14.4021(7) Angstrom, beta = 98.6
49(2)degrees, V = 2112.5(3) Angstrom(3), Z = 4, R = 0.0323, and R(w) =
0.0335; 3, C19H13N3O2SV, M(r) = 398.34, monoclinic, P2(1)/n, a = 12.1
108(10) Angstrom, b = 19.4439(18) Angstrom, c = 7.2351(7) Angstrom; be
ta = 103.012(3)degrees, V = 1660.0(4) Angstrom(3), Z = 4, R = 0.0355,
and R(w) = 0.0376; 4 . CH3CN, C19H12N3O4VNa . CH3CN, M(r) = 461.31, mo
noclinic, P2(1)/c, a = 11.528(1) Angstrom, b = 11.209(1) Angstrom, c =
16.512(2) Angstrom, beta = 103.928(4)degrees, V = 2071.0(5) Angstrom(
3), Z = 4, R = 0.0649, and R(w) = 0.0806; 5 . 2CH(3)OH, C20H10N2O5VNa2
. 2CH(3)OH, M(r) = 519.31, triclinic, P1, a = 12.839(1) Angstrom, b =
8.334(1) Angstrom, 12.201(1) Angstrom, alpha = 106.492(2)degrees, bet
a = 105.408(2)degrees, gamma = 73.465(2)degrees, V = 1175.6(3) Angstro
m(3), Z = 2, R = 0.0894, and R(w) = 0.1043; 10, C28H32N3O5V M(r) = 541
.52, monoclinic, P2(1)/c, a = 11.711(3) Angstrom, b = 18.554(5) Angstr
om, c = 12.335(3) Angstrom, beta = 95.947(9)degrees, V = 2666(2) Angst
rom(3), Z = 4, R = 0.0904, and R(w) = 0.0879. In addition to the synth
esis and crystallographic studies, we report the optical, infrared, ma
gnetic, and electrochemical properties of these complexes. Electron pa
ramagnetic resonance [of oxovanadium(IV) species] and H-1, C-13{H-1},
and V-51 nuclear magnetic resonance [of oxovanadium(V) complex] proper
ties are reported as well. This study represents the firsr systematic
study of vanadium(III), (VO2+)-O-IV, and (VO3+)-O-V species containing
a vanadium-deprotonated amide nitrogen bond.