K. Seetharamiah Nagaraja

Bio: K. Seetharamiah Nagaraja is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topic(s): Thiocyanate & Dithiocarbamate. The author has an hindex of 3, co-authored 4 publication(s) receiving 28 citation(s).

Cobalt(II) Complexes of Creatinine

Abstract: Cobalt(II) complexes of creatinine [Co(creat)2X2] (X = Cl, Br, I or NCS) and [Co(creat)2X2(H2O)2] (X = HCO2, HOCH2CO2 or CNCH2CO2) have been prepared. Their i.r. spectra show an increase in ν(NH) of the cyclic secondary amine group, compared to free ligand (3300 cm−1), indicating that cyclic nitrogen is involved in coordination. The thiocyanate group coordinates through nitrogen and carboxylates coordinate as univalent unidentate ligands. The electronic spectra and magnetic moments suggest a d7 configuration for cobalt: a tetrahedral geometry (4.4 B.M.) for halide and thiocyanate complexes, and an octahedral geometry (5.0 B.M.) for the carboxylate complexes. On heating, the ligand moiety is lost and the respective cobalt halide or cobalt carboxylate is formed, which is converted finally into Co3O4. There is a correlation between the high intensity electronic transitions and the polarographic half-wave potentials.

Reactivity of the tetrathiomolybdate(VI) anion towards hard and soft base chelating agents

Abstract: The interaction of hard base chelating agents (LH) such as 8-quinolinol (oxH), salicylaldehyde (salH) andN-nitrosophenylhydroxylamine (NphaH) with ammonium tetrathiomolybdate(VI), (1), in aqueous solution yields disulphidomolybdenum(VI) complexes, [MoS2L2] The ir absorptions at 540 and 510 cm−1 are assigned tov(Mo-S), which indicate that the two sulphido-groups arecis to each other, The interaction of (1) with soft base chelating agents (SS), such as dithiocarbamates (dtc), dithiophosphate (dtp) and xanthates (xan) yields dimeric sulphido-bridged sulphidomolybdenum(V) complexes, [Mo2S4(SS)2] and with potassium ethylthioxanthate (KEttxan) yields a molybdenum(IV) complex, [Mo(Ettxan)4] The [Mo2S4(R2dtc)2] complexes were also obtained by the interaction of [MoO2(R2dtc)2] with phosphorus pentasulphide in xylene It was concluded that tetrathiomolybdate(VI) undergoes facile reduction when compared with tetraoxomolybdate(VI)

Isothiocyanatooxomolybdenum(V) dithiocarbamates

Abstract: Isothiocyanatooxomolybdenum(V) complexes, [MoO-(NCS)(R2dtc)2] (R=ethyl or dibenzyl; R2=piperidinyl or 4-morpholinyl) have been prepared and characterized. The i.r. spectral bands at 2020 cm−1 are assigned tov(CN) which suggest that thiocyanate coordinates through nitrogen. The bands at 930, 1500 and 960 cm−1 are attributed tov(MoO),v(CN) andv(CS), respectively, and indicate the presence of the MoO3+ moiety and a bidentate dithiocarbamate group. The e.p.r. and electronic spectral data together with magnetic moment values (1.69 B.M.) suggest the presence of one unpaired electron. The complexes are monomeric. The thermal decomposition behaviour of the complexes is reported.

Molybdenum and tungsten

Abstract: The chemistry of these two industrially important metals bears a close general resemblance to that of niobium and tantalum. There is the same emphasis on the highest oxidation state, in this case six. Common to both pairs of metals are such important features as polymeric oxyanions, metal-metal bonding in lower halides, formation of bronzes, a certain paucity of classical co-ordination compounds with a resulting prominence of the binary halide chemistry, and lack of hydrated cations.

Coordination properties of the bioligands creatinine and creatine in various reaction media

Abstract: Data on the ability of the important bioligands creatinine and creatine to form various types of complexes with different metal ions are summarized. The crucial role of the nature of the reaction medium in complex formation with these ligands is emphasized. The conditions for obtaining paramagnetic oligomeric platinum complexes of the “platinum blue” type (resulting from multistep redox and coordination processes) are presented.

Assay of creatinine using the peroxidase activity of copper-creatinine complexes.

Abstract: Objectives: It was our goal to develop a urine dipstick that could measure creatinine with a peroxidase reaction. The simultaneous measurement of albumin and creatinine permits the estimation of the 24-h albumin excretion, an important value in judging existing or likely development of renal failure. A highly sensitive dye-binding dipstick method for albumin exists, and a suitable dipstick for the assay for urine creatinine is described here. Methods: Copper-creatinine and iron-creatinine complexes have peroxidase activity. With 3,3′,5,5′-tetramethylbenzidine (TMB), and diisopropyl benzene dihydroperoxide (DBDH); the peroxidase activity of copper-creatinine and iron-creatinine complexes can be demonstrated. This reaction was used in the assay of urine creatinine either in solution or by a suitably impregnated urine dipstick. Results: Our method based on the peroxidase activity of the copper-creatinine complex has an analytical range for creatinine of 100 mg/L (0.884 mmol/L) to 3000 mg/L (26.52 mmol/L). The creatinine assay is free from most interfering compounds that may be present in urine. Hemoglobin is an interferent, and its effects can be reduced but not eliminated by the addition of 4-hydroxy-2-methyl quinoline. We do not recommend using the dipsticks when visible blood is present or if the dipstick blood test is positive. The copper-creatinine complex oxidizes ascorbic acid; however, we were able to modify the reaction conditions so that ascorbic acid at Discussion: With the simultaneous measurement of creatinine and albumin in urine, the albumin/creatinine ratio can be determined effectively reducing or eliminating the occasional false-negative and false-positive result in those with dilute or concentrated urines, respectively. The dipstick test for these analytes permits the simple identification of individuals with possible albuminuria and could serve well in a point-of-care setting.

Crystal structure, ir-spectrum and electrochemical behaviour of cu(creatinine)2cl2

Abstract: The crystal structure of the little compound has been solved by single-crystal X-ray diffractometry. The CuII ion is located on a two-fold crystallographic axis in a quasi-tetrahedral coordination. The infrared spectrum of the complex was recorded and briefly analyzed in relation to its structural peculiarities. Its electrochemical behaviour was investigated by cyclic voltammetry in methanolic solutions.

Spectroscopic and structural study of the newly synthesized heteroligand complex of copper with creatinine and urea.

Abstract: Study of copper complex of creatinine and urea is very important in life science and medicine. In this paper, spectroscopic and structural study of a newly synthesized heteroligand complex of copper with creatinine and urea has been discussed. Structural studies have been carried out using DFT calculations and spectroscopic analyses were carried out by FT-IR, Raman, UV–vis absorption and fluorescence techniques. The copper complex of creatinine and the heteroligand complex were found to have much increased water solubility as compared to pure creatinine. The analysis of FT-IR and Raman spectra helps to understand the coordination properties of the two ligands and to determine the probable structure of the heteroligand complex. The LIBS spectra of the heteroligand complex reveal that the complex is free from other metal impurities. UV–visible absorption spectra and the fluorescence emission spectra of the aqueous solution of Cu–Crn–urea heteroligand complex at different solute concentrations have been analyzed and the complex is found to be rigid and stable in its monomeric form at very low concentrations.