BALACHANDRAN UNNI NAIR
Articles written in Journal of Chemical Sciences
Volume 106 Issue 3 June 1994 pp 681-689
Balachandran Unni Nair M Kanthimathi K Chandra Raj T Ramasami
The stabilization of chromium(IV) and chromium(V) in aqueous systems has now been made through designed alterations in Franck-Condon barriers for the interconversion of various oxidation states of chromium. Equatorially coordinated macrocyclic and Schiff base ligands influence the reorganizational barriers for the conversion of Cr(III)-Cr(IV)-Cr(V)-Cr(VI) couples such that Cr(IV) and Cr(V) transients of sufficiently long life time can be generated. A series of macrocyclic and Schiff base complexes of Cr(III) has been synthesised and subjected to non-complementary redox reaction with Ce(IV) or electrochemical oxidation. A Cr(IV) macrocyclic complex, Cr(Me4[14]tetraene)(H2O)24+, 1 has been generated in aqueous acidic medium, through electrochemical oxidation. The Ce(IV) oxidation of Cr(III) Schiff base complexes, diaqua[N,N′-ethylenebis(salicylideneiminato) chromium(III)], and diaqua[N,N′-propylenebis(salicylideneiminato) chromium(III)] proceed in two stages with 1 Cr:l Ce(IV) redox stoichiometry. Suffīciently long-lived Cr(IV) intermediates and Cr(V) Schiff base products have been generated. ESR evidence for the formation of Cr(V) Schiff base products and the mechanistic outcome of the oxidation of Cr(III) Schiff bases are discussed.
Volume 108 Issue 3 June 1996 pp 325-325 Modern Trends In Inorganic Chemistry
Volume 108 Issue 3 June 1996 pp 334-334 Modern Trends In Inorganic Chemistry
Volume 109 Issue 4 August 1997 pp 235-248 Inorganic And Analytical
M Kanthimathi Balachandran Unni Nair T Ramasami T Shibahara T Tada
Complexes of general formulation [Cr(Schiff-base)(H2O)2]X, where Schiff-base=1, 2-
Volume 111 Issue 1 February 1999 pp 133-145 Trends In Collagen
R Gayatri Rama Rajaram Balachandran Unni Nair F Chandrasekaran T Ramasami
A molecular insight into the mechanism of stabilisation of collagen against the action of collagenase and wet heat leading to tanning has been gained. The variations in the extent of stabilisation of collagen with the nature of the molecular species of chromium(III) have been demonstrated experimentally. A case has been made to conceive tanning as emerging from an increase in long-range order and chromium(III)-induced molecular assembly of collagen.
Volume 112 Issue 2 April 2000 pp 109-118
Synthesis of cadmium sulphide in pure and mixed Langmuir-Blodgett films of
G Hemakanthi Balachandran Unni Nair Aruna Dhathathreyan
Cadmium sulphide (CdS) nanoparticles were grown by the reaction of sodium sulphide (Na2S) with Langmuir-Blodgett (LB) films of cadmium salts of
Volume 125 Issue 5 September 2013 pp 1161-1168
Abhijit Pal Bhaskar Biswas Merry Mitra Subramaniyam Rajalakshmi Chandra Shekhar Purohit Soumitra Hazra Gopinatha Suresh Kumar Balachandran Unni Nair Rajarshi Ghosh
Synthesis and characterization of a mononuclear Fe(II) compound [Fe(L)](ClO4)2 (1) [L = N-(1-pyridin-2-yl-phenylidene)-N'-[2-({2-[(1-pyridin-2-ylphenylidene)amino]ethyl}amino)ethyl] ethane-1,2-diamine] (
Volume 126 Issue 1 January 2014 pp 65-73
Sriparasara Radhika Kalarical Janardhanan Sreeram Balachandran Unni Nair
New cerium-based ceramic pigments, displaying Ce2Pr0.2Fe$_x$O$_{4.3+y}$ stoichiometry, were obtained at low temperature using a sol-gel method. The powder precursor dissolved in 80% ethylene glycol was precipitated using ammonia and the obtained gel calcined at 800°C for 2 h to yield homogeneous and crystalline particles with a diameter of around 150 nm. The oxide was composed of cerium in its +4 oxidation state and Pr in its +3 oxidation state. The oxides with varying Fe content had an intense red-brown colour, with bandgap energy of around 2.2 eV at 0.1 mol% Fe doping. The near infra red reflectance from these pigments, a measure of their ability to reflect rather than absorb heat waves from sunlight was found to be 82.7%, even in the absence of a white reflective base. Such high near infra red reflectance from these pigments qualify them for being ideal cool pigments for surface coating applications.
Volume 127 Issue 8 August 2015 pp 1375-1381 Regular Articles
DNA binding and cleavage activity of a structurally characterized Ni(II) Schiff base complex
Sarat Chandra Kumar Abhijit Pal Merry Mitra V M Manikandamathavan Chia -Her Lin Balachandran Unni Nair Rajarshi Ghosh
Synthesis and characterization of a mononuclear Ni(II) compound [Ni(L)(H2O)2](NO3)2 [L = N,N'-bis((pyridine-2-yl)phenylidene)-1,3-diaminopropan-2-ol] (
Volume 129 Issue 12 December 2017 pp 1929-1940 REGULAR ARTICLE
Frequency upconversion in catechin assisted LaF₃: Yb³⁺-Er³⁺ square nanoplates
VAIRAPPERUMAL TAMILMANI ABHISHEK KUMAR SONI VINEET KUMAR RAI BALACHANDRAN UNNI NAIR KALARICAL JANARDHANAN SREERAM
Yb ³⁺ -Er³⁺ codoped lanthanum upconverting nanostructures with varying concentration of dopants have been synthesized by catechin method. The prepared upconverting nanostructures were characterized through XRD,TEM,XPS, NIR absorption,TGAandDSCanalysis.TEMstudy confirms the formation of squareshaped nanoplates with size less than 100 nm. XPS peaks around 830–854eV further reveal the formation of LaF ₃ in the prepared samples. Frequency upconversion spectra from the developed nanostructures corresponding to the ²H₁₁/₂, ⁴S₃/₂ → ⁴ I₁₅/₂ and ⁴F₉/₂ → ⁴I₁₅/₂ transitions upon 980nm excitation are reported. Enhancement in the upconversion emission of catechin-based lanthanum nanostructures has been observed when compared with that prepared by ammonium di-n-octadecyldithiophosphate (AODTP) method.
Volume 135, 2023
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