Kiran T Dhavskar

Syntheses, structure and properties of Alkaline-earth metal salts of 4-Nitrophenylacetic acid

AbstractThe synthesis, crystal structure, spectral characteristics and thermal properties of alkaline-earth metal salts of 4-nitrophenylacetic acid (4-npaH) namely, [Mg(H2O)6](4-npa)2⋅4H 2O (4-npa = 4-nitrophenyl-acetate) (1), [Ca(H 2O) 2(4-npa) 2] (2) and [Sr(H 2O) 3(4-npa) 2] ⋅4.5H 2O(3) are reported. In 1, the 4-npa ion functions as a charge balancing counter anion for the octahedral [Mg(H 2O) 6] 2+ unit with the Mg(II) ion situated on a centre of inversion. The two unique lattice water molecules link the [Mg(H 2O) 6] 2+ cations and 4-npa anions with the aid of O-H ⋯O interactions. Compounds 2 and 3 are one-dimensional (1-D) coordination polymers containing an eight coordinated Ca(II) situated in a general position and a nine coordinated Sr(II) located on a twofold axis. The μ2-bridging tridentate binding modes of the crystallographically independent 4-npa ligands in 2 and the unique 4-npa ligand in 3 link the bivalent metal ions into an infinite chain with alternating Ca ⋯Ca separations of 3.989 and 4.009 Å, respectively, and a single Sr ⋯Sr separation of 4.194 Å in the 1-D chain. Graphical AbstractSynthesis, structure and properties of [Mg(H2O)6](4-npa)2·4H2O (4-npa =4-nitrophenylacetate) (1), [Ca(4-npa)2(H2O)2] (2), and [Sr(4-npa)2(H2O)3]·4.5H2O (3) are reported.

Synthesis, crystal structure and properties of magnesium and calcium salts of p-anisic acid

AbstractThe synthesis, crystal structure and properties of the magnesium and calcium salts of p-anisic acid viz. [Mg(H 2O) 6](C 8H7O3) 2⋅2H 2O (C 8H7O3 = p-anisate or 4-methoxybenzoate) (1) and [Ca(H 2O)(C 8H7O3) 2] (2) are reported. The p-anisate ion is not coordinated to Mg(II) and functions as a charge balancing counter anion for the centrosymmetric octahedral [Mg(H 2O) 6] 2+ unit in 1. The unique lattice water molecule links pairs of [Mg(H 2O) 6] 2+cations and p-anisate anions with the aid of O-H ⋯O interactions. The μ2-bridging bidentate and the μ3-bridging tetradentate binding modes of the crystallographically unique p-anisate ligands in (2) result in a two-dimensional (2-D) coordination polymer. Graphical AbstractThe synthesis, crystal structure and properties of a monomeric octahedral magnesium compound [Mg(H2O)6](C8H7O3)2·2H2O (C8H7O3 = p-anisate or 4-methoxybenzoate) and a two dimensional coordination polymeric compound [Ca(H2O)(C8H7O3)2] are reported.

Comments on the paper: Growth structural, spectral, optical and mechanical studies of gamma bis glycinium oxalate (GBGOx) new NLO single crystal by SEST method

Abstract The authors of the title paper (Kalaiselvi et al. Optik 125 (2014) 1825–1828) claim to have synthesized a new nonlinear optical (NLO) gamma bis glycinium oxalate (GBGOx) crystal by slow evaporation solution technique. In this communication, many points of criticism, concerning the characterization of this so called GBGOx NLO crystal are highlighted to prove that the title paper is completely erroneous.

Comments on the paper: ‘Optical reflectance, optical refractive index and optical conductivity measurements of nonlinear optics for l-aspartic acid nickel chloride single crystal’

Abstract We argue that the ‘ L -aspartic acid nickel chloride’ crystal reported by the authors of the title paper (Optics Communications, 291 (2013) 304–308) is actually the well-known diaqua( L -aspartato)nickel(II) hydrate crystal.