The molecular and electronic structure of an unusual cobalt NNO pincer ligand complex

2019 ◽  
Vol 48 (21) ◽  
pp. 7378-7387 ◽  
Author(s):  
Jitendrasingh Rajpurohit ◽  
Maheswaran Shanmugam

An NNO pincer ligand is reduced by three electrons which are stabilized by the mixed-valent cobalt ions, which is extremely rare and structurally characterized with unusual binding mode of pyridine, for the first time. The accurate electronic structure of the complex was determined by various analytical techniques such as XPS, SQUID, EPR etc.

1983 ◽  
Vol 38 (11) ◽  
pp. 1313-1324 ◽  
Author(s):  
Klaus Ackermann ◽  
Peter Hofmann ◽  
Frank H. Köhler ◽  
Hans Kratzer ◽  
Herbert Krist ◽  
...  

Abstract A new one-step synthesis for bis-carbene complexes cis-M(CO)4L2 (M = Cr, Mo, W) containing cyclic carbene ligands L has been developed. These compounds can be oxidized by ferrocenium salts to paramagnetic cation complexes [M(CO)4L2]+ which, for M = Cr, are isolable in the form of their PF6 salts. The chromium compounds with L= 1,3-dimethyl-4-imidazolin-2-ylidene permit for the first time a structural and spectroscopic comparison of a diamagnetic carbene complex with the corresponding paramagnetic cation; the experimental facts are interpreted by molecular orbital calculations.


2019 ◽  
Author(s):  
Victor Y. Suzuki ◽  
Luís Henrique Cardozo Amorin ◽  
Natália H. de Paula ◽  
Anderson R. Albuquerque ◽  
Julio Ricardo Sambrano ◽  
...  

<p>We report, for the first time, new insights into the nature of the band gap of <a>CuGeO<sub>3</sub> </a>(CGO) nanocrystals synthesized from a microwave-assisted hydrothermal method in the presence of citrate. To the best of our knowledge, this synthetic approach has the shortest reaction time and it works at the lowest temperatures reported in the literature for the preparation of these materials. The influence of the surfactant on the structural, electronic, optical, and photocatalytic properties of CGO nanocrystals is discussed by a combination of experimental and theoretical approaches, and that results elucidates the nature of the band gap of synthetized CGO nanocrystals. We believe that this particular strategy is one of the most critical parameters for the development of innovative applications and that result could shed some light on the emerging material design with entirely new properties.</p> <p><b> </b></p>


2001 ◽  
Vol 66 (1) ◽  
pp. 139-154 ◽  
Author(s):  
M. Fátima C. Guedes Da Silva ◽  
Luísa M. D. R. S. Martins ◽  
João J. R. Fraústo Da Silva ◽  
Armando J. L. Pombeiro

The organonitrile or carbonyl complexes cis-[ReCl(RCN)(dppe)2] (1) (R = 4-Et2NC6H4 (1a), 4-MeOC6H4 (1b), 4-MeC6H4 (1c), C6H5 (1d), 4-FC6H4 (1e), 4-ClC6H4 (1f), 4-O2NC6H4 (1g), 4-ClC6H4CH2 (1h), t-Bu (1i); dppe = Ph2PCH2CH2PPh2), or cis-[ReCl(CO)(dppe)2] (2), as well as trans-[FeBr(RCN)(depe)2]BF4 (3) (R = 4-MeOC6H4 (3a), 4-MeC6H4 (3b), C6H5 (3c), 4-FC6H4 (3d), 4-O2NC6H4 (3e), Me (3f), Et (3g), 4-MeOC6H4CH2 (3h); depe = Et2PCH2CH2PEt2), novel trans-[FeBr(CO)(depe)2]BF4 (4) and trans-[FeBr2(depe)2] (5) undergo, as revealed by cyclic voltammetry at a Pt-electrode and in aprotic non-aqueous medium, two consecutive reversible or partly reversible one-electron oxidations assigned as ReI → ReII → ReIII or FeII → FeIII → FeIV. The corresponding values of the oxidation potentials IE1/2ox and IIE1/2ox (waves I and II, respectively) correlate with the Pickett's and Lever's electrochemical ligand and metal site parameters. This allows to estimate these parameters for the various nitrile ligands, depe and binding sites (for the first time for a FeIII/IV couple). The electrochemical ligand parameter show dependence on the "electron-richness" of the metal centre. The values of IE1/2ox for the ReI complexes provide some supporting for a curved overall relationship with the sum of Lever's electrochemical ligand parameter. The Pickett parametrization for closed-shell complexes is extended now also to 17-electron complexes, i.e. with the 15-electron ReII and FeIII centres in cis-{[ReCl(dppe)2]}+ and trans-{FeBr(depe)2}2+, respectively.


Author(s):  
Poulami Pattanayak ◽  
Sankar Prasad Parua ◽  
Debprasad Patra ◽  
Ashoke Prasun Chattopadhyay ◽  
Surajit Chattopadhyay

2017 ◽  
Vol 31 (02) ◽  
pp. 1650263
Author(s):  
J. G. Yan ◽  
Z. J. Chen ◽  
G. B. Xu ◽  
Z. Kuang ◽  
T. H. Chen ◽  
...  

Using first-principles calculation we investigated the structural, electronic and elastic properties of paramagnetic CaFeAs2. Our results indicated that the density of states (DOS) was dominated predominantly by Fe-3[Formula: see text] states at Fermi levels, and stronger hybridization exists between As1 and As1 atoms. Three hole pockets are formed at [Formula: see text] and Z points, and two electronic pockets are formed at A and E points. The Dirac cone-like bands appear near B and D points. For the first time we calculated the elastic properties and found that CaFeAs2 is a mechanically stable and moderately hard material, it has elastic anisotropy and brittleness, which agrees well with the bonding picture and the calculation of Debye temperature ([Formula: see text]).


2014 ◽  
Vol 136 (34) ◽  
pp. 11980-11993 ◽  
Author(s):  
Anna-Corina Schmidt ◽  
Frank W. Heinemann ◽  
Wayne W. Lukens ◽  
Karsten Meyer

RSC Advances ◽  
2016 ◽  
Vol 6 (71) ◽  
pp. 66963-66970 ◽  
Author(s):  
Haiguan Yang ◽  
Junqi Zha ◽  
Peng Zhang ◽  
Yuhao Xiong ◽  
Linjing Su ◽  
...  

CoS, which was prepared using a facile solvothermal method, and characterized using various analytical techniques, was demonstrated for the first time to exhibit intrinsic peroxidase-like activity.


RSC Advances ◽  
2012 ◽  
Vol 2 (8) ◽  
pp. 3437 ◽  
Author(s):  
Abhishek Dutta Chowdhury ◽  
Prinaka De ◽  
Shaikh M. Mobin ◽  
Goutam Kumar Lahiri

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