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81.
Sanghapal D. Sawant Mahesuni Srinivas K.A. Aravinda Kumar G. Lakshma Reddy Parvinder Pal Singh Baldev Singh Amit Kumar Sharma P.R. Sharma Ram A. Vishwakarma 《Tetrahedron letters》2013
A general ligand-free protocol has been described for the recyclable and reusable Cu–Mn catalyzed C–N bond forming cross coupling reaction of arylboronic acids with various amines to form N-arylated amine products in aqueous medium affording excellent yields under ambient conditions, in 3–4 h. 相似文献
82.
Bikshandarkoil R. Srinivasan Jyoti V. Sawant Sarvesh C. Sawant Pallepogu Raghavaiah 《Journal of Chemical Sciences》2007,119(6):593-601
The reaction of barium carbonate with 4-nitrobenzoic acid (4-nbaH) results in the formation of a Ba(II) coordination polymer,
catena-poly[[(pentaaqua)(4-nitrobenzoato-O,O’)barium(II)](μ-4-nitrobenzoato-O,O’)] 1. The polymeric compound [[Ba(H2O)5(4-nba-O,O’)](μ-4-nba-O,O’)]
n
1 was characterized by elemental analysis, IR and UV-Vis spectra, weight loss studies, X-ray powder diffraction and its structure
determined. In 1 five water molecules are coordinated to the central metal and one of the 4-nba ligands is bonded to Ba(II)
in a bidentate manner (4-nba-O,O’) through the carboxylate O atoms. The [(pentaaqua)(4-nitrobenzoato-O,O’)barium(II)] units
are linked into an infinite one-dimensional chain along b-axis with the aid of the second 4-nba anion, which functions as
a bridging bidentate (μ-4-nba-O,O’) ligand. This results in nine coordination around each Ba(II) ion in the coordination polymer. A long Ba⋯Ba distance
of 6.750(1) ? is observed between adjacent Ba(II) ions in the chain and the oxygen atoms of the carboxylate group and the
nitro functionalities of the 4-nba ligand are involved in several O-H⋯O and C-H⋯O interactions.
Dedicated to the memory of Late Prof. Bhaskar G. Maiya 相似文献
83.
84.
The lattice parameter,a, increases with the increase of Ti4+ substitution while it decreases with the increase of Ge4+ substitution in Cu1+x
A
x
Fe2–2x
O4 compounds [A=Ti4+, Ge4+Sn4+]. On substitution of Sn4+,a does not vary. CuFe2O4 exhibits single domain (SD) behaviour that changes to multi domain (MD) type on Ti4+ substitution. On Ge4+ substitution initially all the compositions exhibit SD behaviour while forx>0.2 they show MD behaviour. All Sn4+ substituted compositions exhibit SD behaviour. The Curie temperature decreases on addition of Ti4+, Sn4+ and Ge4+. The magnetic momentn
B (77 K) initially increases and then decreases with the substitution of Ti4+, Ge4+, and Sn4+. This is explained by cation distribution and reduction of Fe3+ ions.The authors wish to thank Prof. R. N. Patil for encouragment and useful discussion. One of the authors (B.L.P.) is grateful to UGC (New Delhi) for granting Teacher Fellowship for Ph.D. course. 相似文献
85.
Thin film of Bi2Co0.1V0.9O5.35 is deposited by using spray pyrolysis technique on platinum-coated stainless steel substrate. Impedance measurements done
in the frequency range 1 to 10 MHz and in the temperature range 502 to 720 K revealed two relaxation processes with distinguishable
time constants. The first corresponds to the grain interior charge transfer while the second could be due to grain boundary.
The change in polarization seems to be associated with hopping of charge carriers showing Arrhenius behavior with increase
in temperature. The relaxation frequency of grain interior transport for the thin film ranges from 96 kHz to 2.59 MHz. The
blocking factor was found to be increasing with increase in temperature at low temperature region from 502 to 640 K. At higher
temperature above 640 K, diffusive nature of grain boundaries is inferred with the decrease in blocking factor. The same inference
is derived by specific grain boundary conductivity calculations since specific grain boundary conductivity decreases in low
temperature region while it increases rapidly at higher temperature. These observations prove the grain boundaries to be blocking
in lower temperatures while at higher temperatures above 640 K they turn diffusive. These changes are attributed to structural
phase transition, or ordering of vacancies in Bi2Co0.1V0.9O5.35 films. 相似文献
86.
JPC – Journal of Planar Chromatography – Modern TLC - Enicostemma littorale (Chota-Chirayata or Mamejava) is a glabrous perennial herb belonging to the family Gentianaceae. This plant... 相似文献
87.
Dinesh N. Sawant 《Tetrahedron letters》2010,51(20):2758-381
Conditions for a FeCl3/PPh3-catalyzed and palladium-, copper-, amine free-Sonogashira coupling reaction of aryl halides with terminal alkynes are reported. The protocol was applicable to a wide variety of substituted aryl iodides and alkynes with different steric and electronic properties and gave excellent yields of the desired coupling products. 相似文献
88.
Some mixed ligand complexes of the type [M(L)(en or phen)(X)2]; where M = Mn(II), Co(II) or Ni(II); L = 2-phenyl-3-(benzylamino)-1,2-dihydroquinazolin-4(3H)-one; en = ethylenediamine, phen = 1,10-phenanthroline; X = N3
− or NCS− have been prepared. All the complexes were characterized by physico-chemical, spectroscopic and thermal studies. On the basis
of electronic spectra and magnetic susceptibility measurements, an octahedral geometry has been proposed for all the complexes.
The phen complexes are thermally more stable than the en complexes. The electrochemical behavior of the Ni(II) complexes showed that the complexes of phen are reduced at more positive potential compared to the corresponding en complexes. 相似文献
89.
N. K. Chaudhuri R. M. Sawant D. D. Sood 《Journal of Radioanalytical and Nuclear Chemistry》1999,240(3):993-1011
Literature data on the stability constants of the fluoride complexes of the actinides in different oxidation states have been
compiled. In order to have a reasonable inter-comparison, the stability constant (β1) values obtained in diverse ionic strength media are converted to so called thermodynamic stability constants, β
1
0
using the DAVIES equation (a modification of Debye-Huckel equation). A correlation of the β
1
0
values with the fundamental properties of the actinide ions using various models available in the literature has been attempted.
Using the values of inonic radii and best available values of the stability constants of a large number of metal ions from
recent compilations a comparative study of the various models or relations available in the literature has been tried. For
metal ions in general, the semi-empirical relation recently developed by BROWN, SYLVA and ELLIS (BSE equation)_gives the best
correlation. In an attempt to accommodate the unusual trend in the stability constants of the tetravalent actinides a modification
in a parameter of the BSE equation has been proposed. Good agreement between the theoretically calculated and experimentally
determined values for actinides in different oxidation states is obtained in most of the cases. Further improvements in theoretical
relation as well as experimental data are required for better correlation. 相似文献
90.
Shirish K. Phanse Shriya Sawant Harinder Singh Sudeshna Chandra 《Molecules (Basel, Switzerland)》2022,27(22)
Essential oils (EOs) are naturally occurring volatile aromatic compounds extracted from different parts of plants. They are made up of components like terpenes, phenols, etc., and are chemically unstable and susceptible to oxidative deterioration, leading to reduced shelf-life and overall degradation of the product. Encapsulation of EOs in a matrix can prevent degradation of the active ingredient and improve the shelf-life. In this paper, we report encapsulation of Dhavana oil (Artemisia pellen) in a modified starch matrix using a spray-drying technique. Physico-chemical properties of neat and encapsulated Dhavana oil were studied. We selected two powder bases: CaCO3 and TALC and, loaded neat and encapsulated Dhavana oil in it, studied their stability and interaction with the base matrices at 3 °C, 22 °C and 45 °C up to 2 months under closed conditions and one week at 22 °C and 45 °C under open condition. Thermal degradation pattern was studied for neat and encapsulated Dhavana oil and modified starch. Release of primary active component of neat and encapsulated Dhavana oil from the base matrices was evaluated with GCMS. Stability study and release mechanism were elucidated to understand the release pattern in different base powders under similar conditions. Retention of hydroxydhavanone was found to be better in TALC than CaCO3, and therefore, the former can be considered a suitable base matrix for developing a stable powder formulation with an optimum release of the oil. Dhavana oil is known for its anti-microbial activity, and hence, neat and encapsulated Dhavana oil was tested on different bacterial and fungal strains. The encapsulated oil depicted good anti-microbial efficacy against various bacterial and fungal strains, which is a step forward for developing anti-microbial formulations. Thus, the reported work will provide helpful information on cosmetic formulation and, therefore, be useful for perfumery, food, and cosmetic industries. 相似文献