Structural and spectroscopic studies of transition metal nitrite complexes. VI. Crystal structures and spectra of Hexakis(imidazole)nickel(II) dinitrate, trans-Tetrakis(2-methylimidazole)dinitritonickel(II) and cis-Tetrakis(2-methylimidazole)-(nitrito-O,O')nickel(II) nitrate-methanol (2/1)

1981 ◽  
Vol 34 (10) ◽  
pp. 2113 ◽  
Author(s):  
AJ Finney ◽  
MA Hitchman ◽  
CL Raston ◽  
GL Rowbottom ◽  
AH White
Keyword(s):  
Crystal Structures ◽  
Symmetry Axis ◽  
Spectroscopic Properties ◽  
Spectroscopic Studies ◽  
Ligand Field ◽  
Coordination Geometry ◽  
Distorted Octahedral ◽  
Relative Field ◽  
Ligand Coordination ◽  
Fourfold Symmetry

The crystal structures and spectroscopic properties of the complexes cis-tetrakis(2-methy1imidazole)-(nitrito-O,O')nickel(II) nitrate-methanol (2/1) and trans-tetrakis(2-methylimidazole)dinitritonickel(II) are reported. The nitrite group in the former compound chelates, giving a distorted octahedral ligand coordination geometry. The ligand stereochemistry in the second complex is also a distorted octahedron, with both anions coordinating as trans nitrito groups though with significantly different Ni-O bond lengths and the nickel(II) ion being raised out of the plane of the four imidazole ligand nitrogen atoms towards the closer nitrite group. The Ni-O bond directions also deviate substantially from the fourfold symmetry axis in this latter complex. These distortions apparently occur in order to minimize ligand-ligand repulsions, particularly those associated with the amine methyl substituents. The electronic spectra of both complexes show significant band splittings due to the departure of the ligand field from regular octahedral symmetry and these are discussed in terms of the relative field strengths of the imidazole and nitrito ligands. The structure of hexakis(imidazole)nickel(II) nitrate (redetermination) is also reported.

Coordination geometry in bis(di-2-pyridylamine)copper(II) complexes. Crystal structures and spectroscopic properties of [Cu(L)2(NCS)2][Cu(L)2(NCS)]X, X= , I−

2006 ◽  
Vol 59 (16) ◽  
pp. 1813-1824 ◽  
Author(s):  
Sujittra Youngme ◽  
Jaturong Phatchimkun ◽  
Narongsak Chaichit ◽  
Chaveng Pakawatchai ◽  
Ilpo Mutikainen ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Spectroscopic Properties ◽  
Coordination Geometry

Ligandenfeldspektroskopische Untersuchungen an Übergangsmetall -Aluminium -Tetraalkoxiden / Ligand Field Spectroscopic Studies of Transition Metal Aluminium-Tetraalkoxides

1979 ◽  
Vol 34 (2) ◽  
pp. 262-265 ◽  
Author(s):  
Eberhard Stumpp ◽  
Uwe Hillebrand
Keyword(s):  
Field Theory ◽  
Transition Metal ◽  
Spectral Data ◽  
Spectral Properties ◽  
Spectroscopic Studies ◽  
Octahedral Coordination ◽  
Ligand Field ◽  
Ligand Field Theory ◽  
Distorted Octahedral Coordination ◽  
Distorted Octahedral

Abstract The preparation and the electronic spectral properties of compounds M[Al(OR)4]2 (M = Co, Ni, Cu and R = CH3, C2H5, n-C3H7, n-C4H9) are described. The spectral data are used in conjunction with ligand field theory in deducing the structures of the compounds. The spectrum of green Ni[Al(OR)4]2 is interpreted as a Ni(OR)6 octahedron sharing faces with two Al(OR)4 tetrahedrons. It is proposed that Co 2+ and Cu 2+ are in a distorted octahedral coordination. The alkoxide ligands have been fitted into the spectrochemical and the nephelauxetic series. They are close to H2O in this series.

scholarly journals Crystal structures of (μ2-η2,η2-4-hydroxybut-2-yn-1-yl 2-bromo-2-methylpropanoate-κ4C2,C3:C2,C3)bis[tricarbonylcobalt(II)](Co—Co) and [μ2-η2,η2-but-2-yne-1,4-diyl bis(2-bromo-2-methylpropanoate)-κ4C2,C3:C2,C3]bis[tricarbonylcobalt(II)](Co—Co)

2014 ◽  
Vol 70 (7) ◽  
pp. 9-13
Author(s):  
C. John McAdam ◽  
Stephen C. Moratti ◽  
Brian H. Robinson ◽  
Jim Simpson ◽  
Roderick G. Stanley
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Coordination Geometry ◽  
Carbonyl Ligands ◽  
Axis Direction ◽  
Distorted Octahedral Coordination ◽  
Dicobalt Octacarbonyl ◽  
Distorted Octahedral Coordination Geometry ◽  
Distorted Octahedral ◽  
Cluster Cores

The title compounds, [Co2(C8H11BrO3)(CO)6], (1), and [Co2(C12H16Br2O4)(CO)6], (2), result from the replacement of two carbonyl ligands from dicobalt octacarbonyl by the alkynes 4-hydroxybut-2-ynyl 2-bromo-2-methylpropanoate and but-2-yne-1,4-diyl bis(2-bromo-2-methylpropanoate), respectively. Both molecules have classic tetrahedral C2Co2cluster cores with the CoIIatoms in a highly distorted octahedral coordination geometry. The alkyne ligands both adopt acis-bent conformation on coordination. In the crystal structure of (1), classical O—H...O and non-classical C—H...O contacts form inversion dimers. These combine with weak O...O and Br...O contacts to stack the molecules into interconnected columns along theb-axis direction. C—H...O and C—H...Br contacts stabilize the packing for (2), and a weak Br...O contact is also observed. Interconnected columns of molecules again form along theb-axis direction.

Structural and spectroscopic studies of transition metal nitrite complexes. IX.Crystal structures and spectroscopic properties of polymeric [Ni(C2H8N2)2-(NO2)] ClO4, its mononuclear zinc analogue, cis-Bis(ethane-1,2-diamine)(nitrito-O,O')zinc(II) perchlorate, and the complexes cis-(N,N,N',N'-Tetramethylethane-1,2-diamine)di(nitrito-O,O')-nickel(II) and -zinc(II)

1981 ◽  
Vol 34 (10) ◽  
pp. 2159 ◽  
Author(s):  
AJ Finney ◽  
MA Hitchman ◽  
CL Raston ◽  
GL Rowbottom ◽  
AH White
Keyword(s):  
Nickel Complex ◽  
Zinc Complex ◽  
Spectroscopic Properties ◽  
Spectroscopic Studies ◽  
Amine Nitrogen ◽  
Alternative Description ◽  
Distorted Octahedral ◽  
Steric Factors ◽  
The Difference ◽  
Infrared Frequencies

The crystal structures of the title compounds are reported. The complex [Ni(C2H8N2)2(NO2)] ClO4 is found to be an infinite polymer with trans N,O-bridging nitrite groups. The zinc analogue of this contains mononuclear units involving a symmetrically chelated nitrite group. The two compounds formed with N,N,N',N'-tetramethylethane-1,2-diamine are isostructural, with the metal having a distorted octahedral ligand environment provided by the amine nitrogen atoms and two chelating nitrite groups. However, while the nitrite ions in the nickel complex are chelated approximately symmetrically, the Zn-O bonds trans to the amine nitrogen atoms (2.30 �) are much longer than those in the cis positions (2.07 �), and an alternative description of the geometry of the zinc complex is as a highly distorted tetrahedral arrangement involving essentially monodentate nitrito groups. The difference in stereochemistry between these two complexes is apparently caused by electronic rather than steric factors, and comparison is also made with the geometry reported for the iso-structural copper complex. The electronic spectra of the two nickel(II) complexes are discussed in relation to their structures, and the infrared frequencies reported for the nitrite groups are correlated with the observed coordination geometries.

Two Metal Complexes of the Macrocyclic Ligand 1,4,7-Triazacyclodecane (tacd). Crystal Structures of [Zn(tacd)2](ClO4)2 and [Cu(tacd)2]Br2.4H2O

1995 ◽  
Vol 48 (1) ◽  
pp. 139 ◽  
Author(s):  
XM Chen ◽  
YX Yao ◽  
KL Shi ◽  
TCW Mak
Keyword(s):  
Metal Complexes ◽  
Crystal Structures ◽  
Macrocyclic Ligand ◽  
Octahedral Coordination ◽  
Coordination Geometry ◽  
X Ray ◽  
X Ray Crystallography ◽  
Distorted Octahedral

Two metal complexes of 1,4,7-triazacyclodecane ( tacd ), [Zn( tacd )2] (ClO4)2 (1) and [Cu( tacd )2] Br2.4H2O (2), have been prepared and characterized by X-ray crystallography. Crystals of (1) are monoclinic, P21/n, a 9.506(2), b 10.279(3), c 11.505(2) Ǻ, β 91.29(2)°; crystals of (2) are orthorhombic, Pbca, a 12.035(3), b 13.673(3), c 14.248(2) Ǻ. The zinc(II) atom in (1) is surrounded in a distorted octahedral N6 environment with Zn-N bonds at 2.121(5)-2.131(4) Ǻ; the copper(II) atom in (2) adopts an elongated octahedral coordination geometry with the Cu-N bonds at 2.066(4)-2.294(5) Ǻ.

Structural and spectroscopic studies of transition metal nitrite complexes. I. Crystal structures and spectra of trans-Bis(ethane- 1,2 diamine)dinitronickel(II), trans-Bis[N, N-dimethyl(ethane- 1,2-diamine)]dinitritonickel(II) and trans-bis[N,N'-dimethyl(ethane-1,2 diamine)]dinitronickel(II) monohydrate

1981 ◽  
Vol 34 (10) ◽  
pp. 2047 ◽  
Author(s):  
AJ Finney ◽  
MA Hitchman ◽  
CL Raston
Keyword(s):  
Transition Metal ◽  
Crystal Structures ◽  
Spectroscopic Properties ◽  
Spectroscopic Studies ◽  
Chelate Rings

The crystal structures of the trans complexes bis(ethane-1,2-diamine)dinitronickel(II) (1), bis[N,N-dimethyl(ethane-1,2-diarnine)]dinitritonickel(II) (2) and bis[N,N'-dimethyl(ethane-1,2-diamine)]dinitronickel(II) monohydrate (3) are described, (1) and (2) being redeterminations of previously reported structures. The complexes formed by the substituted amines have significantly different geometries, both in the manner of coordination of the nitrite ligands, and in the conformations adopted by the diamine chelate rings. These differences can be explained in terms of the particular steric requirements of the amine substituents. The changes in nitrite geometry which occur upon coordination, and the spectroscopic properties of the complexes are discussed.

Structural and spectroscopic studies of transition metal nitrite complexes. VII. Crystal structures and spectra of two dinuclear and trinuclear species with stoichiometry [Ni(methylpyridine)2(NO2)2] containing bridging nitrite groups

1981 ◽  
Vol 34 (10) ◽  
pp. 2125 ◽  
Author(s):  
AJ Finney ◽  
MA Hitchman ◽  
CL Raston ◽  
GL Rowbottom ◽  
AH White
Keyword(s):  
Crystal Structures ◽  
Visible Region ◽  
Spectroscopic Studies ◽  
Coordination Sites ◽  
Ligand Coordination ◽  
Amine Ligands ◽  
Single Oxygen Atom ◽  
Single Oxygen ◽  
Species Being ◽  
Oxygen Bond

The crystal structures of the dimer [Ni(γmpy)2(NO2)2]2,2C6H6 and the trimer [Ni(βmpy)2(NO2)2]3,- C6Hs (γmpy = 4-methylpyridine, βmpy = 3-methylpyridine) are reported, the latter being the redetermination of a structure described previously. The ligand coordination geometry in each oligomer is essentially octahedral, with neighbouring nickel(II) ions being bridged by two nitrite groups, one through a single oxygen atom and the second through an oxygen and the nitrogen atom. The amine ligands occupy trans coordination sites with the terminal bond positions in both species being taken up by chelating nitrite ions. In both compounds the oligomers pack so that the amine rings form sheets with potential voids in the lattice being filled by clathrated benzene molecules. The electronic spectra of the complexes in the visible region are unusual, showing peaks centred at c. 17500 and c. 20500 cm-1, and the assignment of these is discussed. The infrared stretching frequencies of the nitrite groups in these and other compounds are found to correlate well with the observed nitrogen-oxygen bond lengths.

Synthesis, crystal structure and spectroscopic properties oftrans-dibromidobis(2,2-dimethylpropane-1,3-diamine-κ2N,N′)chromium(III) perchlorate

2015 ◽  
Vol 71 (5) ◽  
pp. 351-356 ◽  
Author(s):  
Dohyun Moon ◽  
Jong-Ha Choi
Keyword(s):  
Complex Cation ◽  
Complex Salt ◽  
Spectroscopic Properties ◽  
Field Analysis ◽  
Distorted Octahedral Geometry ◽  
Ligand Field ◽  
X Ray Diffraction ◽  
Distorted Octahedral ◽  
Overlap Model ◽  
Similar Complex

The title complex salt,trans-anti-[CrBr2(Me2tn)2]ClO4(where Me2tn = 2,2-dimethylpropane-1,3-diamine, C5H14N2), was prepared and its structure determined by single-crystal X-ray diffraction at 100 K. The asymmetric unit contains three conformationally similar complex cations and three perchlorate anions. In each complex cation, the CrIIIcentre is coordinated by four N atoms of two chelating Me2tn ligands in the equatorial plane and by two Br atoms in atrans-axial arrangement, to give a distorted octahedral geometry. Interionic contacts are dominated by extensive hydrogen bonding, involving the NH groups of the Me2tn ligand as donors and the anion O atoms or coordinated Br atoms as acceptors, resulting in two-dimensional layers in thebcplane. Ligand field analysis based on the angular overlap model, and IR and electronic spectroscopic properties, are also discussed.

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