Calculation of the electronic structure of square-planar complexes of Pt (II)

1967 ◽  
Vol 2 (1) ◽  
pp. 81-83
Author(s):  
B. P. Kovarskaya
Keyword(s):  
Electronic Structure ◽  
Square Planar ◽  
Square Planar Complexes

MO study of Td-D4h equilibrium in complexes of transition metals. Equilibrium in tetrachloro complexes of atoms of the first transition row

1982 ◽  
Vol 47 (6) ◽  
pp. 1556-1569 ◽  
Author(s):  
Petr Pelikán ◽  
Marek Liška
Keyword(s):  
Experimental Data ◽  
Electronic Structure ◽  
Chemical Reactions ◽  
Central Atom ◽  
Equilibrium Constants ◽  
Cndo Method ◽  
Oxidation Degree ◽  
Square Planar ◽  
Complexes Of Transition Metals ◽  
Square Planar Complexes

The CNDO method in UHF version has been used for study of equilibrium of configuration isomers of tetrahedral and square-planar tetrachloro complexes of the first transition row atoms in the oxidation degree II (Mn(II), Fe(II), Co(II), Ni(II), Cu(II)). From the results it follows that the ability (conditioned by electronic structure of the central atom) to form the square-planar complexes decreases in the series Mn(II) > Fe(II) > Co(II) > Ni(II) > Cu(II). Several authors state the fact that the most important task of quantum chemistry is to develop procedures for calculation of rate and equilibrium constants of chemical reactions1,2. At the same time it is emphasized that these procedures should be independent of experimental data. By this term the authors mean such experimental data which are in some way connected with the reaction studied, and not the general experimental experience which (after transformation into axioms) can represent a basis of the used method.

MO study of Td-D4h equilibrium in complexes of transition metals. II. Equilibrium in tetrafluoro and tetrabromo complexes of atoms of the first transition row

1984 ◽  
Vol 49 (12) ◽  
pp. 2837-2856 ◽  
Author(s):  
Peter Pelikán ◽  
Marek Liška
Keyword(s):  
Electronic Structure ◽  
Transition Metals ◽  
Central Atom ◽  
Spin States ◽  
Cndo Method ◽  
Oxidation Degree ◽  
High Spin States ◽  
Square Planar ◽  
Complexes Of Transition Metals ◽  
Square Planar Complexes

The CNDO method for transition metals in the UHF version has been used to study the equilibrium of configuration isomers of tetrahedral and square-planar tetrafluoro and tetrabromo complexes of the first transition row atoms in the oxidation degree II (Mn(II), Fe(II), Co(II), Ni(II), Cu(II) both in low-spin and in high-spin states. The results show that the ability (given by electronic structure of the central atom) to form the square-planar complexes decreases monotonously in the series: Mn(II) > Fe(II) > Co(II) > Ni(II) > Cu(II). With respect to the effect of the electronic structure of ligands, the same ability decreases in the series: F- > Cl- > Br-.

Chlorine nuclear quadrupole resonance in some chloro complexes of divalent copper

1971 ◽  
Vol 24 (10) ◽  
pp. 1993 ◽  
Author(s):  
DE Scaife
Keyword(s):  
Nuclear Quadrupole Resonance ◽  
Covalent Bonding ◽  
Divalent Copper ◽  
Chloro Complexes ◽  
35Cl Nucleus ◽  
Square Planar ◽  
Bonding Interaction ◽  
Quadrupole Resonance ◽  
Square Planar Complexes ◽  
Nuclear Quadrupole

Nuclear quadrupole resonance for the 35Cl nucleus has been observed in some chloro complexes of divalent copper. Square-planar complexes each show two resonance lines, with the following frequencies (at 77�K): (CH3NH3)2CuCl4, 10.780, 12.157 MHz; (C2H5NH3)2CuCl4, 10.817, 12.074 MHz; (enH2)CuCl4, 10.271, 11.901 MHz; and (C3H7NH3)2CuCl4 at 223�K, 11.290 and 11.781 MHz. NH4CuCl3, containing dimeric Cu2Cl62- units, has resonances, at 77�K, at 11.907, 11.993, and 12.448 MHz. The trigonal pyramidal anion in Co(NH3)6CuCl5 has two resonances at 9.642 and 10.352 MHz at 77�K. ��� These results are compared with previous results for copper chloro complexes, and the implications of covalent bonding are discussed. In particular, it is suggested that the long-bond interaction between units in square-planar complexes amounts to 7-16% of the bonding interaction within the units.

Electronic structure of nitrogen square planar copper complexes in Langmuir-Blodgett films

1992 ◽  
Vol 210-211 ◽  
pp. 519-520
Author(s):  
Stéphane Carniato ◽  
Henri Roulet ◽  
Georges Dufour ◽  
Serge Palacin ◽  
André Barraud ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Copper Complexes ◽  
Langmuir Blodgett ◽  
Square Planar ◽  
Langmuir Blodgett Films

Extended X-ray absorption fine structure and multiple-scattering simulation of nickel dithiolene complexes Ni[S2C2(CF3)2]2n(n= −2, −1, 0) and an olefin adduct Ni[S2C2(CF3)2]2(1-hexene)

2015 ◽  
Vol 22 (1) ◽  
pp. 124-129 ◽  
Author(s):  
Weiwei Gu ◽  
Hongxin Wang ◽  
Kun Wang
Keyword(s):  
Fine Structure ◽  
Multiple Scattering ◽  
Edge Structure ◽  
X Ray ◽  
Absorption Fine ◽  
Square Planar ◽  
Square Planar Complexes ◽  
Uv Visible ◽  
Edge Features ◽  
X Ray Absorption

A series of Ni dithiolene complexes Ni[S2C2(CF3)]2n(n= −2, −1, 0) (1,2,3) and a 1-hexene adduct Ni[S2C2(CF3)2]2(C6H12) (4) have been examined by NiK-edge X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine-structure (EXAFS) spectroscopies. Ni XANES for1–3reveals clear pre-edge features and approximately +0.7 eV shift in the NiK-edge position for `one-electron' oxidation. EXAFS simulation shows that the Ni—S bond distances for1,2and3(2.11–2.16 Å) are within the typical values for square planar complexes and decrease by ∼0.022 Å for each `one-electron' oxidation. The changes in NiK-edge energy positions and Ni—S distances are consistent with the `non-innocent' character of the dithiolene ligand. The Ni—C interactions at ∼3.0 Å are analyzed and the multiple-scattering parameters are also determined, leading to a better simulation for the overall EXAFS spectra. The 1-hexene adduct4presents no pre-edge feature, and its NiK-edge position shifts by −0.8 eV in comparison with its starting dithiolene complex3. Consistently, EXAFS also showed that the Ni—S distances in4elongate by ∼0.046 Å in comparison with3. The evidence confirms that the neutral complex is `reduced' upon addition of olefin, presumably by olefin donating the π-electron density to the LUMO of3as suggested by UV/visible spectroscopy in the literature.

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