UV-Visible Absorption Studies of Gossypol-Metal Cation Complexes in Acetonitrile Solution

1991 ◽  
Vol 24 (10) ◽  
pp. 1265-1273 ◽  
Author(s):  
Bronislaw Marciniak ◽  
Halina Kozubek ◽  
Bogumil Brzezinski
Keyword(s):  
Metal Cation ◽  
Acetonitrile Solution ◽  
Visible Absorption ◽  
Absorption Studies ◽  
Uv Visible ◽  
Cation Complexes

scholarly journals One-pot synthesis and UV-Visible absorption studies of novel tricyclic heterocycle tethered Xanthene-1,8-diones

2015 ◽  
Vol 127 (5) ◽  
pp. 803-810 ◽  
Author(s):  
THIRUMAL YEMPALA ◽  
BALASUBRAMANIAN SRIDHAR ◽  
SRINIVAS KANTEVARI
Keyword(s):  
One Pot ◽  
Visible Absorption ◽  
One Pot Synthesis ◽  
Absorption Studies ◽  
Uv Visible

Occlusion of Foreign Molecules in Primary Asphaltene Aggregates from Near-UV–Visible Absorption Studies

2017 ◽  
Vol 31 (2) ◽  
pp. 1370-1375 ◽  
Author(s):  
Igor N. Evdokimov ◽  
Aleksey A. Fesan ◽  
Aleksandr P. Losev
Keyword(s):  
Visible Absorption ◽  
Absorption Studies ◽  
Uv Visible

ChemInform Abstract: One-Pot Synthesis and UV-Visible Absorption Studies of Novel Tricyclic Heterocycle Tethered Xanthene-1,8-diones.

ChemInform ◽  
2015 ◽  
Vol 46 (49) ◽  
pp. no-no
Author(s):  
Thirumal Yempala ◽  
Balasubramanian Sridhar ◽  
Srinivas Kantevari
Keyword(s):  
One Pot ◽  
Visible Absorption ◽  
One Pot Synthesis ◽  
Absorption Studies ◽  
Uv Visible

Optical Properties and Structural Studies on Nd3+ Doped Borate Glasses Containing Heavy Metal Oxide

2012 ◽  
Vol 584 ◽  
pp. 207-211 ◽  
Author(s):  
Vijaya Chikkaveeraiah Veeranna Gowda ◽  
K.R Sardar Pasha ◽  
M. Sudhakar Reddy ◽  
C. Narayana Reddy
Keyword(s):  
Optical Band Gap ◽  
Band Gap Energy ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Absorption Studies ◽  
Amorphous Nature ◽  
Uv Visible ◽  
Quenching Method ◽  
Bi2o3 Content

Abstract. Neodymium doped sodium bismuth borate (Na2O-Bi2O3-B2O3) glasses were prepared by melt quenching method. Amorphous nature of the glass is confirmed through the X-ray diffraction study. Density of the investigated glasses increases systematically with Bi2O3 concentration. Glass transition temperature decrease slightly with increase of Bi2O3 content and could be due to increase in the number of weaker Bi-O linkages by stronger Nd-O linkages. Fourier Transform - Infrared (FTIR) spectroscopy has been carried out. The IR spectra of the glasses reveal that the strong network consisting of diborate units and is unaffected by the variation of Nd3+ concentration. UV-Visible absorption studies have been performed on these glasses to examine the optical spectra and the optical band gap energy has been calculated. The intensity of the absorption band increases with the increase of Nd3+ concentration. This is due to the formation of non-bridging oxygens (NBO’s) in the structure.

scholarly journals ComparativeIn VitroBinding Studies of TiCl2(dpme)2, Ti(ada)2(bzac)2, and TiCl2(bzac)(bpme) Titanium Complexes with Calf-Thymus DNA

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Pamita Awasthi ◽  
Nitesh Kumar ◽  
Raj Kaushal ◽  
Mohan Kumar ◽  
Shrikant Kukreti
Keyword(s):  
Circular Dichroism ◽  
Binding Constants ◽  
Blue Shift ◽  
Binding Mode ◽  
Visible Absorption ◽  
Calf Thymus ◽  
Absorption Studies ◽  
Uv Visible ◽  
Ct Dna ◽  
Circular Dichroïsm

The binding of TiCl2(dpme)2(1), (dpme = 6,6′-dimethyl-2,2′-bipyridine), Ti(ada)2(bzac)2(2), (ada = adamantylamine; bzac = benzoylacetone), and TiCl2(bzac)(bpme) (3), (bpme = 4,4′-dimethyl-2,2′-bipyrdine) with calf thymus (ct) DNA has been studied by UV-visible spectroscopy, thermal denaturation, and circular dichroism spectroscopy. In UV-visible study complexes1,2, and3showed red, blue, and red shifts, respectively, upon the addition of ct-DNA along with a significant hyperchromism. The intrinsic binding constants (Kb) calculated from UV-visible absorption studies were 2.3 × 103 M−1, 3.3 × 103 M−1and, 7.1 × 103 M−1for complexes1,2, and3, respectively. The change in melting temperature (ΔTm) was calculated to be 2-3°C for each complex. Circular dichroism (CD) study showed blue shift for complex2and red shift for complexes1and3along with rise in molecular ellipticity upon the addition of complexes. Results suggest a binding mode of complex2different than1and3.

scholarly journals Metal cation complexes as dispersing agents for non-aqueous powder suspensions

2021 ◽  
Author(s):  
Paulina Zubrzycka ◽  
Marta Radecka ◽  
Thomas Graule ◽  
Michael Stuer
Keyword(s):  
Metal Cation ◽  
Dispersing Agents ◽  
Cation Complexes

Remarkable kinetic stability of α-thiocarbamoyl substituted 4-methoxybenzylcations

1998 ◽  
Vol 76 (12) ◽  
pp. 1910-1915 ◽  
Author(s):  
Robert A McClelland ◽  
Victoria E Licence ◽  
John P Richard ◽  
Kathleen B Williams ◽  
Shrong-Shi Lin
Keyword(s):  
Key Words ◽  
Strong Interaction ◽  
Rate Constants ◽  
Flash Photolysis ◽  
Visible Absorption ◽  
Methyl Group ◽  
Thioamide Group ◽  
Azide Ion ◽  
Uv Visible ◽  
Leaving Groups

4-Methoxybenzyl cations bearing α-(N,N-dimethylcarbamoyl) and α-(N,N-dimethylthiocarbamoyl) substituents have been generated photochemically upon irradiation of precursors with pentafluorobenzoate or 4-methoxybenzoate leaving groups. The ions have been observed with flash photolysis in 40:60 acetonitrile:water and in 50:50 methanol:water, and rate constants were measured for their decay in solvent alone and for their capture by azide ion. The cations so studied and their lifetimes in 40% acetonitrile are 6, ArC+H-CONMe2, 0.6 μs; 2, ArC+H-CSNMe2, 7 ms; and 4, ArC+(CH3)-CSMe2, 6 ms, where Ar = 4-MeOC6H4. The cation 4 reacts with solvent by elimination of a proton from the α-methyl group, and the rate constant for solvent addition must be less than 1 s-1. The CSNMe2 substituted cations are 105-107-fold longer lived than analogs where the thioamide group has been replaced with an α-methyl. The UV-visible absorption spectra of these two cations also show significant differences from those of typical 4-methoxybenzyl cations. Thus, both the lifetimes and spectra point to a strong interaction of the benzylic centre with the thioamide group. Key words: flash photolysis, thiocarbamoyl stabilized carbocation, photosolvolysis.

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