Complexes of Dimethylaminophosphazenes with Metal Ions

1975 ◽  
Vol 53 (12) ◽  
pp. 1765-1774 ◽  
Author(s):  
H. P. Calhoun ◽  
N. L. Paddock ◽  
J. N. Wingfield
Keyword(s):  
Metal Ions ◽  
High Spin ◽  
Electronic Spectra ◽  
Molecular Structures ◽  
Metal Coordination ◽  
Ligand Field ◽  
Steric Interactions ◽  
Trigonal Bipyramidal ◽  
Ligand Field Parameters ◽  
Distorted Trigonal Bipyramidal

The preparation of complexes DDPN.2MCl2 (M = Mn, Fe, Co, Zn ), DDPN.M(NO3)2, (M = Mn, Co, Ni, Cu, Zn), (DDPN = N6P6(NMe2)12) ), and N9P9(NMe2)18.2CoCl2 is described. All the complexes of the hexamer are of the high spin type and contain the cations DDPNMX+ (X = Cl, NO3 ). Their infrared and electronic spectra show that their molecular structures are essentially the same as those established crystallographically for the chlorocations (M = Co, Cu ), in which, as a consequence of steric interactions, the metal has a distorted trigonal-bipyramidal environment. The complex with Cu(NO3)2 is exceptional in that the DDPNCu2+ ion is formed in ionizing solvents, with a change in the stereochemistry of the metal. Coordination localizes π-electrons in nitrogen, weakens the ring bonds, and strengthens the exocyclic P—N bonds, as expected theoretically. Approximate values of ligand field parameters of the Co(NO3)2 and Ni(NO3)2 complexes are similar to those of complexes formed by simple amines; the phosphazenes act as σ-donors, their acceptor levels not being used significantly.

Synthesis and Crystal and Molecular Structures of the N,N-Dimethylethanol-aminogallane and N,N-Dimethylethanolaminogallium Dimethyl Dimers

1975 ◽  
Vol 53 (1) ◽  
pp. 58-66 ◽  
Author(s):  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Least Squares ◽  
Molecular Structures ◽  
Methyl Groups ◽  
Steric Interactions ◽  
Full Matrix ◽  
Space Group ◽  
Trigonal Bipyramidal Geometry ◽  
Crystal And Molecular Structures ◽  
Trigonal Bipyramidal ◽  
Distorted Trigonal Bipyramidal

Crystals of the N,N-dimethylethanolaminogallane dimer 1a are monoclinic, a = 8.540(1), b = 7.0433(7), c = 12.227(6) Å, β = 92.94(3)°, Z = 2, space group P21/c and crystals of the N,N-dimethylethanolaminogallium dimethyl dimer 1b are orthorhombic, a = 15.608(3), b = 11.655(2), c = 10.266(2) Å, Z = 4, space group Pccn. Both structures were determined by Patterson and Fourier syntheses and were refined by full-matrix least-squares procedures to final R values of 0.039 and 0.053 for 1062 and 1155 reflections with 1 ≥ 3σ(I) respectively. Both structures feature well-separated centrosymmetric dimeric units occurring via the formation of four-membered Ga2O2 rings. The five-coordinate gallium atoms have distorted trigonal bipyramidal geometry. Steric interactions between methyl groups in 1b are believed responsible for the lengthening of the axial Ga—N distance from 2.279(3) in 1a to 2.471(4) Å in 1b. Other bond distances are: for 1a; Ga—O (axial), 2.053(3), Ga—O, 1.911(3), Ga—H, 1.50(7) and 1.73(5), O—C, 1.369(5), N—C, 1.466 – 1.485(6), C—C, 1.512(7), and mean C—H, 1.05; for 1b; Ga—O (axial), 2.078(3), Ga—O, 1.913(3), Ga—C, 1.936(6) and 1.948(7), O—C, 1.382(7), N—C, 1.452–1.482(7−8), C—C, 1.516(9), and mean C—H, 1.01 Å.

Infrared and Electronic Spectral Studies of Cobalt(II) and Nickel(II) Complexes of N-Allyl Urea and N-Allyl Thiourea

1972 ◽  
Vol 50 (16) ◽  
pp. 2603-2609 ◽  
Author(s):  
P. P. Singh ◽  
I. M. Pande
Keyword(s):  
Magnetic Susceptibility ◽  
Electronic Spectra ◽  
Electrical Conductance ◽  
Spectral Studies ◽  
Ligand Field ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data ◽  
Halide Complexes ◽  
Ligand Field Parameters ◽  
Allyl Thiourea

Complexes of N-allyl urea (NAU) and N-allyl thiourea (NATU) with cobalt (II) and nickel (II) halides and perchlorates have been prepared and characterized by electrical conductance, magnetic susceptibility, infrared and electronic spectra. Infrared spectra suggest coordination in NAU through oxygen and in NATU through nitrogen. The electronic spectra and magnetic susceptibility data indicate tetrahedral and octahedral stereochemistry for cobalt (II) and nickel (II) halide complexes, respectively. The various ligand field parameters Dq, B′, and β calculated for these complexes show about 25 and 11% covalency for Co (II) and Ni (II), respectively, and suggest a weak ligand field.

scholarly journals Spectroscopic studies of benzoxazole-2-thione complexes. Derivatives of cobalt(II) and nickel(II) halides

1976 ◽  
Vol 54 (1) ◽  
pp. 85-90 ◽  
Author(s):  
Carlo Preti ◽  
Giuseppe Tosi
Keyword(s):  
Magnetic Susceptibility ◽  
Ir Spectra ◽  
Electronic Spectra ◽  
Spectroscopic Studies ◽  
Ligand Field ◽  
Conductivity Measurements ◽  
Derivatives Of ◽  
Ligand Field Parameters ◽  
Cobalt And Nickel

The preparation of some complexes of benzoxazole-2-thione with halides of cobalt(II) and nickel(II) is reported. The complexes of cobalt(II) and nickel(II) are tetrahedral of the type ML2X2 with the exception of NiLBr2. The complexes have been studied by means of magnetic susceptibility measurements, infrared and far ir spectra, electronic spectra, and conductivity measurements. The ligand behaves as monodentate N-bonded. The various ligand field parameters, Dq, B′, and β show about 60 and 80% of covalency in the cobalt(II) and nickel(II) complexes respectively and suggest a medium strong ligand field. The spectroscopy parameters of cobalt and nickel derivatives confirm the presence of CoN2X2 and NiN2X2 chromophores.

scholarly journals Synthesis and Characterization of Two New Coordination Polymers Constructed from Azobenzene-4, 4′-Dicarboxylic Acid with Zinc (Ii) and Cd (Ii) 2, 2′-Bipyridine

2018 ◽  
Vol 7 ◽  
pp. 39-42
Author(s):  
Pramod Kumar Yadav
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Dicarboxylic Acid ◽  
Coordination Polymers ◽  
Molecular Structures ◽  
Metal Coordination ◽  
Synthesis And Characterization ◽  
Metal Coordination Polymers

Two transition metal coordination polymers [Zn(4,4′-ADA)(bpy)]n (1) and [Cd(4,4′-ADA)(bpy)(H2O)2]n (2) have been assembled from azobenzene-4,4′- dicarboxylic acid (H2ADA) with the help of 2,2′-bipyridine (bpy) ligand. The different molecular structures for complexes 1 and 2 formed from the same ligand (H2ADA) reveals the fact that organic linkers display different coordination preferences at different metal ions.

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