Longato, Bruno and Montagner, Diego and Zangrando, Ennio (2009) Role of the ancillary ligands on the stabilization of the imino-oxo tautomer of 1-methylcytosine in PtII complexes. Dalton Transactions (13). pp. 2400-2405. ISSN 1477-9226

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Abstract

The mixed nucleobases complexes cis-[L2Pt{1-MeTy(-H)}(1-MeCy,N3)]NO3 (L = PPh3, 1a; PMePh2, 1b), containing the N(3)-deprotonated 1-methylthymine (1-MeTy(-H)) and the neutral 1-methylcytosine (1-MeCy) have been prepared and characterised. The compounds were obtained by reacting the hydroxo complexes cis-[L2Pt(μ-OH)]2(NO3)2 with 1-methylthymine (1-MeTy), followed by the addition of 1 equivalent of 1-MeCy. In solution of DMSO, DMF or chlorinated solvents, 1a converts quantitatively into the isomer cis-[L2Pt{1-MeTy(-H)}(1-MeCy,N4)]NO3 (2a) containing the tautomeric form of the cytosine stabilized through the coordination at the N(4) atom, as shown by single-crystal X-ray analysis. The structural determination of 2a shows the presence in the unit cell of two crystallographic independent complexes having similar conformation, with a different orientation of the two nucleobases (head–head and head–tail) according to the presence of both isomers in solution. Complex 1b, having the less hindered PMePh2 ligands, in DMSO solution, contains the tautomeric forms of the cytosine in equilibrium and the migration of the metal from the N(3) to N(4) site occurs only to a minor extent.

Item Type:	Article
Keywords:	ancillary ligands; stabilization;imino-oxo tautomer;
Academic Unit:	Faculty of Science and Engineering > Chemistry
Item ID:	7039
Identification Number:	https://doi.org/10.1039/B818514J
Depositing User:	Diego Montagner
Date Deposited:	21 Mar 2016 17:39
Journal or Publication Title:	Dalton Transactions
Publisher:	Royal Society of Chemistry
Refereed:	Yes
URI:	Publisher
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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