Spectroscopic Studies of the EutT Adenosyltransferase from Salmonella enterica: Evidence of a Tetrahedrally Coordinated Divalent Transition Metal Cofactor with Cysteine Ligation

The preparation of a series of novel compounds of general formula [Ni5L4(NO2)8(OH)2] formed by ethane-1,2-diamine or one of five N-substituted ethane-1,2-diamines (L) is described. The crystal and molecular structures of the ethane-1,2-diamine, N,N'-diethylethane-1,2-diamine and N,N-dimethylethane-1,2-diamine complexes are reported. Each compound contains a planar, pentameric arrangement of nickel(II) ions, linked by bridging hydroxide and nitrite ligands. The details of the nitrite bridges differ among the complexes, causing differences in their electronic and infrared spectra. The structural variations are probably caused by the differing steric requirements of the amine substituents.

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Molecular orbital and spectroscopic studies of triple bonds between transition-metal atoms. 2. The d5-d5 Re2Cl4(PR3)4 compounds

Journal of the American Chemical Society ◽

10.1021/ja00347a015 ◽

1983 ◽

Vol 105 (9) ◽

pp. 2606-2611 ◽

Cited By ~ 21

Author(s):

Bruce E. Bursten ◽

F. Albert Cotton ◽

Phillip E. Fanwick ◽

George G. Stanley ◽

Richard A. Walton

Keyword(s):

Transition Metal ◽

Molecular Orbital ◽

Spectroscopic Studies ◽

Triple Bonds ◽

Metal Atoms ◽

Transition Metal Atoms

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Synthesis and spectroscopic studies of new binuclear transition metal complexes of Schiff bases derived from 4,6-diacetylresorcinol

Transition Metal Chemistry ◽

10.1007/s11243-007-0245-z ◽

2007 ◽

Vol 32 (7) ◽

pp. 889-901 ◽

Cited By ~ 44

Author(s):

Adel A. A. Emara ◽

Omima M. I. Adly

Keyword(s):

Transition Metal ◽

Metal Complexes ◽

Schiff Bases ◽

Transition Metal Complexes ◽

Spectroscopic Studies

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Structural and spectroscopic studies of transition metal nitrite complexes. V. Crystal structures and spectra of trans-Tetrakis(pyridine)dinitritonickel(II)-pyridine (1/2), trans-Tetrakis(4-methylpyridine)dinitritonickel(II) and trans-Tetrakis(pyrazole)-dinitritonickel(II)

Australian Journal of Chemistry ◽

10.1071/ch9812095 ◽

1981 ◽

Vol 34 (10) ◽

pp. 2095 ◽

Cited By ~ 22

Author(s):

AJ Finney ◽

MA Hitchman ◽

CL Raston ◽

GL Rowbottom ◽

BW Skelton ◽

...

Keyword(s):

Hydrogen Bonding ◽

Transition Metal ◽

Crystal Structures ◽

Electronic Spectra ◽

Spectroscopic Studies ◽

Molecular Structures ◽

Aromatic Rings ◽

Paddle Wheel ◽

Crystal And Molecular Structures ◽

Infrared Frequencies

The crystal and molecular structures of the compounds [Ni(py)4(ONO)2],2py, [Ni(γmpy),(ONO)2] and [Ni(prz)4(ONO)2] are reported.�All three are trans nitrito complexes, the pyridine (py) compound containing two pyridine molecules of solvation. The aromatic rings in the first two complexes adopt 'paddle wheel' conformations with pitch angles varying between 40 and 70�. The nitrite ions are positioned so as to minimize repulsive interactions with the amines, and it seems likely that these groups bond through oxygen rather than nitrogen because this allows a lesser degree of interligand steric interference. The amine rings in [Ni(prz)4(ONO)2] are orthogonal to the plane containing the nickel and coordinated pyrazole nitrogen atoms; the nitrito groups are disordered between two inequivalent positions, each of which involves hydrogen bonding with the pyrazole NH groups. The nitrite infrared frequencies are similar to those observed for other nickel(II) nitrito complexes except that the antisymmetric NO stretching mode of one of the groups in the pyrazole complex is much lower in energy than expected, being in the range normally associated with a nitrogen-bonded or chelated nitrite group. It is suggested that this deviation may be caused by the hydrogen bonding in the complex. The electronic spectra of the compounds yield 10Dq values of 9100 and 8500 cm-1 for the nitrite ligands in [Ni(py)4(ONO)2] and Ni(prz)4(ONO)2], respectively, placing the nitrito group towards the weaker end of the spectro-chemical series.

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