Structural and coordinating properties of platinum(II) chloride complexes with polypyridyl ligands. Single crystal X-ray structure of [Pt(ddpq)Cl-2]center dot H2O (ddpq=6,7-dimethyl-2,3-di(2-pyridyl)quinoxaline)
J. Granifo et al., Structural and coordinating properties of platinum(II) chloride complexes with polypyridyl ligands. Single crystal X-ray structure of [Pt(ddpq)Cl-2]center dot H2O (ddpq=6,7-dimethyl-2,3-di(2-pyridyl)quinoxaline), INORG CHIM, 321(1-2), 2001, pp. 209-214
The X-ray crystallographic study of the methylated complex [Pt(ddpq)Cl-2] (
ddpq = 6,7-dimethyl-2,3-di(2-pyridyl)quinoxaline) has been carried out and
compared with that of the non-methylated derivative [Pt(dpq)Cl-2] (dpq = 2,
3-di(2-pyridyl)quinoxaline). In both complexes the polypyridyl ligands are
bonded bidentally by using their pyridyl nitrogen atoms. Also, the crystal
structures of both complexes present a graphitic pi-pi overlapping involvin
g pairs of adjacent quinoxaline rings. But, the extension of the overlappin
g is less in the methylated derivate than in the non-methylated one. Also,
the complex [Pt(dhp)Cl-2] (dhp = 2,3-di(2-pyridyl)-5,6-dihydropyrazine) was
synthesized to study the bonding feature by using a ligand containing a no
n-aromatic pyrazine moiety. In spite of forming species of similar formula
to that of the dpq and ddpq ligands, [Pt(dhp)Cl-2], the dhp ligand is bonde
d to the Pt(II) by using one pyridyl nitrogen and one dihydropyrazine nitro
gen atom, as shown by H-1 NMR spectroscopy. (C) 2001 Elsevier Science B.V.
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