Rajesh published the artcileMonomeric Cu(II) complexes with tetradentate bis(benzimidazole) ligand; synthesis, EPR, spectral and electrochemical studies, Category: catalysis-chemistry, the publication is Polyhedron (1998), 17(16), 2607-2615, database is CAplus.
1:1 Copper(II) complexes Cu(L)X2¡¤nH2O (X = Cl–, NO3–, OAc– and HCOO–) with the tetradentate ligand 1,2-bis(2-benzimidazolylmethoxy)benzene (L) were prepared X-band EPR spectra of the above complexes examined as a frozen DMSO/DMF solution indicate g¡¬ > g¡Í > 2.0 and show four or less than four g¡¬ lines and a broadening of the g¡Í component suggesting a lowered site symmetry for the copper(II) ion. The g¡Í component of all the complexes show nitrogen superhyperfine structure. A clear five line pattern is found in the g¡Í region with BN ? 15G¡À1 for Cu(L)X2¡¤nH2O complexes indicating that two nitrogen from the benzimidazole ring are coordinated to the central CuII in the equatorial basal plane while the other two positions in the sphere are occupied by the anionic ligand (X). With ClO4– as the anion, the 1:2 complex [Cu(L)2](ClO4)2 results. The X-band EPR spectra of [Cu(L)2](ClO4)2 shows a clear nine line SHF structure on the g¡Í component indicating the presence of four nitrogen atoms coordinated to the central CuII atom; this confirms the retention of two ligands around CuII in solution MO coefficients ¦Â1 and ¦Â1‘ were evaluated from the expression used by Manoharan and Rogers. The trends of ¦Â1 and ¦Â1‘ indicate increasing electron delocalization on nitrogen atom as the authors change the exogenous ligand from formate/acetate-chloride to nitrate. The covalency parameter, ¦Á2, also was evaluated and reflects the decreasing trend of covalency in the order nitrate > chloride ¡Ý acetate > formate for complexes containing these ligands. This trend of order is in conformity with that obtained from MO coefficients All the complexes exhibit a visible band with ¦Ëmax in the 625-690 nm region in DMF, suggesting a distorted geometry for copper(II) ion in the present series of complexes. Cyclic voltammetric studies of copper(II) complexes reveal that the E1/2 for the CuII/CuI couple shifts to most neg. value with HCOO– and OAc– anionic ligands implying that these anion stabilize the CuII state whereas E1/2 data for NO3– reveals that this anion destabilizes the CuII state. A plot of visible band energy vs. E1/2 shows that as the energy of the dx2-y2 orbital decreases, an anodic shift in CuII ¡ú CuI reduction potential is observed
Polyhedron published new progress about 5411-14-3. 5411-14-3 belongs to catalysis-chemistry, auxiliary class Carboxylic acid,Benzene,Ether, name is 2,2-(1,2-Phenylenebis(oxy))diacetic acid, and the molecular formula is C10H10O6, Category: catalysis-chemistry.
Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia