<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Kathawate, Laxmi</style></author><author><style face="normal" font="default" size="100%">Gejji, Shridhar P.</style></author><author><style face="normal" font="default" size="100%">Yeole, Sachin D.</style></author><author><style face="normal" font="default" size="100%">Verma, Prakash L.</style></author><author><style face="normal" font="default" size="100%">Puranik, Vedavati G.</style></author><author><style face="normal" font="default" size="100%">Salunke-Gawali, Sunita</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">First naphthosemiquinone complex of K+ with vitamin K3 analog: experiment and density functional theory</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Molecular Structure</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">C-13 NMR</style></keyword><keyword><style  face="normal" font="default" size="100%">DFT</style></keyword><keyword><style  face="normal" font="default" size="100%">hydrogen bonding</style></keyword><keyword><style  face="normal" font="default" size="100%">Naphthosemiquinone</style></keyword><keyword><style  face="normal" font="default" size="100%">Phthiocol</style></keyword><keyword><style  face="normal" font="default" size="100%">Vitamin K3</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2015</style></year><pub-dates><date><style  face="normal" font="default" size="100%">MAY</style></date></pub-dates></dates><publisher><style face="normal" font="default" size="100%">ELSEVIER SCIENCE BV</style></publisher><pub-location><style face="normal" font="default" size="100%">PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS</style></pub-location><volume><style face="normal" font="default" size="100%">1088</style></volume><pages><style face="normal" font="default" size="100%">56-63</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Synthesis and characterization of potassium complex of 2-hydroxy-3-methyl-1,4-naphthoquinone (phthiocol), the vitamin K3 analog, has been carried out using FT-IR, UV-Vis, H-1 and C-13 NMR, EPR, cyclic voltammetry and single crystal X-ray diffraction experiments combined with the density functional theory. It has been observed that naphthosemiquinone binds to two K+ ions extending the polymeric chain through bridging oxygens O(2) and O(3). The crystal network possesses hydrogen bonding interactions from coordinated water molecules showing water channels along the c-axis. C-13 NMR spectra revealed that the complexation of phthiocol with potassium ion engenders deshielding of C(2) signals, which appear at delta = similar to 14.6 ppm whereas those of C(3) exhibit up-field signals near delta similar to 6.9 ppm. These inferences are supported by the M06-2x based density functional theory. Electrochemical experiments further suggest that reduction of naphthosemiquinone results in only a cathodic peak from catechol. A triplet state arising from interactions between neighboring phthiocol anion lead to a half field signal at g = 4.1 in the polycrystalline X-band EPR spectra at 133 K. (C) 2015 Elsevier B.V. All rights reserved.&lt;/p&gt;</style></abstract><custom3><style face="normal" font="default" size="100%">&lt;p&gt;Foreign&lt;/p&gt;</style></custom3><custom4><style face="normal" font="default" size="100%">&lt;p&gt;1.78&lt;/p&gt;</style></custom4></record></records></xml>