@article { ISI:000323468500032,
	title = {Synthesis and molecular structure of a zinc complex of the vitamin K-3 analogue phthiocol},
	journal = {Journal of Molecular Structure},
	volume = {1048},
	year = {2013},
	month = {SEP},
	pages = {223-229},
	publisher = {ELSEVIER SCIENCE BV},
	address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS},
	abstract = {<p>The complex [Zn(phthiocol)(2)(H2O)(2)]; 1, where phthiocol is 2-hydroxy-3-methyl-1,4-naphthoquinone, has been synthesized and characterized by elemental analysis, FT-IR, H-1 NMR, UV-vis spectroscopy, thermogravimetric (TG) analysis, electrochemical and single crystal X-ray diffraction studies. The v(C=O) stretch shifts to lower frequencies upon complexation of phthiocol to Zn2+. H-1 NMR spectra show an upfield shift of the benzenoid ring protons in 1. There is a bathochromic shift of the LMCT band in the UV-vis spectra of 1. Single crystal X-ray structure of 1 show distorted octahedral geometry around Zn2+. Two phthiocol ligands are in plane with the metal, while water molecules are trans to this plane. Coordination of deprotonated phthiocol ligands is {\textquoteleft}trans, trans{\textquoteright} to Zn2+. Intra as well as intermolecular interactions are observed in 1. Molecules of 1 show three dimensional network through C-H center dot center dot center dot O and O-H center dot center dot center dot O interactions. Additional anodic peaks are observed in cyclic voltammogram of phthiocol ligand due to oxidation of reduced species formed during reduction. One-electron reduction of 1 is shown to be reversible and DFT studies define this redox event as ligand-centered. (c) 2013 Elsevier B.V. All rights reserved.</p>},
	keywords = {hydrogen bonding, Naphthoquinone, Phthiocol, Trans coordination, Vitamin K-3, Zinc complex},
	issn = {0022-2860},
	doi = {10.1016/j.molstruc.2013.05.057},
	author = {Kathawate, Laxmi and Sproules, Stephen and Pawar, Omkar and Markad, Ganesh and Haram, Santosh K. and Puranik, Vedavati G. and Salunke-Gawali, Sunita}
}
@article { ISI:000330147900013,
	title = {Synthesis, characterization and molecular structures of homologated analogs of 2-bromo-3-(n-alkylamino)-1,4-napthoquinone},
	journal = {Journal of Molecular Structure},
	volume = {1056},
	year = {2014},
	month = {JAN},
	pages = {97-103},
	publisher = {ELSEVIER SCIENCE BV},
	address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS},
	abstract = {<p>Four analogues of 2-bromo-3-(n-alkylamino)-1,4-napthoquinone (where n-alkyl is methyl in L-1Br, ethyl in L-2Br, propyl in L-3Br and butyl in L-4Br) are synthesized and characterized. A reaction mechanism is proposed for the formation of L-1 Br to L-4Br from the starting material 2,3-dibromo-1,4-naphthoquinone. The v(N-H) frequency in the FT-IR spectra is affected by the intramolecular hydrogen bonding in L-1Br to L-4Br and is observed similar to 3267 cm(-1) in L-2Br. A shift of similar to 25 cm(-1) is observed in the v(C-Br) frequency in all the compounds as compared to 2,3-dibromo-1,4-naphthoquinone (627 cm(-1)). A broad charge transfer band is observed between 400 and 600 nm in the UV-Vis spectra, which imparts red colour to all the compounds. Molecular structures of L-2Br and L-3Br were studied by single crystal X-ray diffraction studies. Molecules of L-2Br crystallize in Pca2(1), whereas the molecule L-3Br crystallizes in the P-1 space group. Molecules of L-2Br forms a polymeric chain through N-H...O interaction and forms beautiful butterfly like arrangement of molecules when viewed down the {\textquoteleft}a{\textquoteright} axis. Ladder like polymeric chain of molecules is observed in L-3Br via C-H...O and N-H...O interactions. Every alternating neighbouring chains of L-3Br, show pi-pi stacking interactions between the quinonoid rings of the molecules, however this interaction is not observed in L-2Br. (C) 2013 Elsevier B.V. All rights reserved.</p>},
	keywords = {2, 3-Dibromo-1, 4-naphthoquinone, Aminonaphthoquinone, hydrogen bonding, Michael addition, pi-pi stacking},
	issn = {0022-2860},
	doi = {10.1016/j.molstruc.2013.10.016},
	author = {Salunke-Gawali, Sunita and Pawar, Omkar and Nikalje, Milind and Patil, Rishikesh and Weyhermueller, Thomas and Puranik, Vedavati G. and Konkimalla, V. Badireenath}
}
