N-Acyl isocyanide complexes of iron(II) porphyrins. Access to mixed-ligand species using a substitute for carbon monoxide

1984 ◽  
Vol 23 (25) ◽  
pp. 4398-4399 ◽  
Author(s):  
M. Le Plouzennec ◽  
A. Bondon ◽  
G. Simonneaux
Keyword(s):  
Carbon Monoxide ◽  
Mixed Ligand ◽  
Ligand Species

Synthesis and Structural Systematics of Nitrogen Base Adducts of Group 2 Salts. VI. Mixed Oligodentate-Aliphatic-Base/Oxygen Ligand Adducts

1996 ◽  
Vol 49 (1) ◽  
pp. 87 ◽  
Author(s):  
AF Waters ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
Mixed Ligand ◽  
Metal Salts ◽  
Precise Description ◽  
Nitrogen Base ◽  
X Ray ◽  
Oxygen Ligand ◽  
Group 2 ◽  
Ligand Species

In the course of synthesizing oligodentate aliphatic nitrogen base adducts of Group 2 metal salts, a number of mixed- ligand species have been isolated with oxygen ligands , and characterized by room-temperature single-crystal X-ray studies. BaCl2.4en.H2O ≡[(en)4Ba(OH2)] Cl2 (1) is monoclinic, P 21/c, a 9.456(4), b 14.953(6), c 14.82(1) Ǻ, β 100.78(6)°, Z = 4 f.u ., R 0.043 for No 1862 independent 'observed' (I > 3σ(I)) diffractometer reflections. Ba -N range between 2.900(9) and 2.97(1) Ǻ, and Ba-O is 2.779(8) Ǻ in the nine-coordinate BaN8O environment. CaCl2.2dien.H2O ≡ [( dien )2Ca(OH2) Cl ] Cl (2) is monoclinic, P 21/c, a 10.808(4), b 11.999(4), c 15.71(1) Ǻ, β 123.58(4)°, Z = 4 f.u ., R 0.050 for No 3134; CaBr2.2dien.2H2O ≡ [( dien )2Ca(OH2)2] Br2 (3) is monoclinic, P 21/c, a 18.001(3), b 11.983(6), c 21.562(5) Ǻ, β 124.97(2)°, Z = 8 f.u ., R 0.045 for No 2858; CaBr2.2dien.2MeOH ≡ [( dien )2Ca( HOMe )2] Br2 (4) is orthorhombic, P212121, a 16.620(8), b 12.78(1), c 9.765(4) Ǻ, Z = 4 f.u ., R 0.073 for No 878. In (2)-(4), the cation configurations are similar, being of the form [L2Ca( dien )2], L (L') being the unidentate ligand, with the eight-coordinate calcium environments [L2Ca(N3)2] in a common isomeric configuration, the two ligands L being cis in an array of quasi-2 symmetry. Ca- Cl in (2) is 2.834(1) Ǻ; Ca-N generally range between 2.52(5) and 2.64(1) Ǻ; Ca-O(H2O) is 2.418(2) in (2), 2.434(7)-2.496(7) Ǻ in (3), while Ca-O( MeOH ) in (4) are 2.43(2) and 2.43(2) Ǻ. [Mg(HOMe)6] I2.2tmeda (5) ( tmeda = Me2N(CH2)2NMe2), orthorhombic, Pbca, a 23.423(8), b 15.306(4), c 9.345(1) Ǻ, Z = 4 f.u ., R 0.052 for No 1928, provides a usefully precise description for the centrosymmetric cation, Mg-O being 2.069(4), 2.080(4), 2.096(5) Ǻ, with Mg-O-C 128.4(4) l28.9(4), l29.7(4)°. [( tmeda )SrI2 ( HOMe )3].½tmeda (6), monoclinic, P 21/c, a 7.730(1), b 35.493(9), c 11.081(2) Ǻ, β 126.49(1)°, R 0.042 for No 3161, has a seven-coordinate, quasi-pentagonal bipyramidal SrN2I2O3 array about the metal with trans-iodines.

Spectral reflectance studies of some metal chelates in the adsorbed state

1969 ◽  
Vol 47 (20) ◽  
pp. 3902-3906 ◽  
Author(s):  
R. W. Frei ◽  
H. Zeitlin
Keyword(s):  
Spectral Reflectance ◽  
Metal Chelates ◽  
Mixed Ligand ◽  
Adsorbed State ◽  
Unusual Behavior ◽  
Electronic Polarization ◽  
Visible Transmittance ◽  
Polarization Theory ◽  
Adsorption Phenomena ◽  
Ligand Species

Adsorption phenomena of a group of metal chelates of pyridine-2-aldehyde-2-quinolylhydrazone (PAQH) have been investigated. Formulas have been postulated for the chelates on the basis of ultraviolet and visible transmittance and reflectance spectra, ion exchange studies of charges, and chromatographic and temperature behavior. Shifts of spectra with varying adsorbents have been explained on the basis of the electronic polarization theory. Unusual behavior of the chelates has been observed on starch and cellulose and the existence of mixed ligand species due to interaction of adsorbents with the chelates has been suggested.

Some studies on synergic extraction of mixed ligand species of uranium(VI)

1988 ◽  
Vol 121 (1) ◽  
pp. 149-159
Author(s):  
K. V. Chetty ◽  
P. M. Mapara ◽  
Rajendra Swarup ◽  
S. K. Patil
Keyword(s):  
Mixed Ligand ◽  
Synergic Extraction ◽  
Ligand Species

scholarly journals The computed distribution of copper(II) and zinc(II) ions among seventeen amino acids present in human blood plasma

1971 ◽  
Vol 121 (3) ◽  
pp. 549-555 ◽  
Author(s):  
P. S. Hallman ◽  
D. D. Perrin ◽  
Ann E. Watt
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Complex Formation ◽  
Blood Plasma ◽  
Equilibrium Distribution ◽  
Mixed Ligand ◽  
The Other ◽  
Human Blood Plasma ◽  
Plasma Composition ◽  
Ligand Species

The equilibrium distribution of copper(II) and zinc(II) ions among a mixture of 17 amino acids has been computed from stability-constant and blood-plasma-composition data. At pH7.4, 98% of the copper(II) in the simulated plasma solution is co-ordinated to histidine and cystine, predominantly as the mixed-ligand complexes [Cu·His·Cystine]− and [Cu·H·His·Cystine]. Approximately half of the zinc(II) is co-ordinated to cysteine and histidine, but appreciable complex-formation occurs with most of the other amino acids. Stability constants are given for copper(II) and zinc(II) amino acid complexes, including some mixed-ligand species, at 37°C and I=0.15m.

Preparation of 2- and 4-substituted 3-hydroxy-5-methylfurans and the aluminum and gallium complexes of 3-hydroxy-5-methyl-2-(N-methylformamido)furan

1994 ◽  
Vol 72 (5) ◽  
pp. 1362-1369 ◽  
Author(s):  
T.G. Lutz ◽  
D.J. Clevette ◽  
H.R. Hoveyda ◽  
V. Karunaratne ◽  
A. Nordin ◽  
...  
Keyword(s):  
Solid State ◽  
Formation Constants ◽  
Mixed Ligand ◽  
Complexing Agent ◽  
Equilibrium Studies ◽  
Solution Equilibrium ◽  
Model Studies ◽  
Solution Studies ◽  
Ligand Species ◽  
Potentiometric Data

In model studies designed to study the synthesis of potentially hexadentate chelates based on the linkage of three furan rings to a triamine via amide linkages, new 2- and 4-substituted 3-hydroxy-5-methylfurans have been prepared. Particularly, 3-hydroxy-5-methyl-(N-methylformamido)furan (Hahm) and its Al and Ga complexes (M(ahm)3) have been prepared and thoroughly characterized by a variety of techniques, in the solid state and in solution. Solution equilibrium studies (μ = 0.6 M NaCl, 25 °C) uncovered a complicated set of equilibria in the Al3+/Hahm system; the solution potentiometric data were best explained by the presence of mixed ligand (HL = Hahm, L− = ahm−) hydroxo species [Al3(OH)4L3]2+ and [Al(OH)2L2]−, in addition to the expected [AlLn](3−n)+ (n = 1, 2, 3) species. Further solution studies at HL:M ratios of 3:1 (μ = 0.15 M NaCl, 25 °C) showed that Hahm is a relatively weak complexing agent for both Al and Ga, forming tris-ligand species with overall formation constants of 1019.5 and 1020.6, respectively.

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