ISSN:
1434-1948
Keywords:
Palladium
;
Platinum
;
Bidentate nitrogen ligands
;
p-Quinone
;
Alkenes
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Compounds of the type M(N∩N-κN)(nq)2 and M2(μ2-N∩N)(μ2-pbq)2, in which nq = 1,4-naphthoquinone, pbq = 1,4-benzoquinone, and N∩N is a monodentate or bridging ligand of the α-diimine type, were obtained from reactions of Pd(dba)2 in toluene with the 3,3′-annelated-2,2′-bipyridines: 4,5-diazafluoren-9-one (dafo) and 4,5-diazafluorene (dafe) in the presence of the appropriate p-quinone. In the corresponding reactions with 2,2′-bipyridine (bpy), 1,10-phenanthroline (phen), 2,2′-bipyrimidine (bpym), N,N′-dicyclohexyl-1,4-diaza-1,3-butadiene (chex-dab), bis[N-(o,o′-diisopropyl)phenylimino]acenaphthene (o,o′-iPr2-bian) and 5,6-dihydro-1,10-phenanthroline (dh-phen) only complexes of the type M(N∩N-κ2N)(Q) were formed (Q = nq, pbq). The structures of the complexes have been established by NMR in solution and by X-ray diffraction in the solid state; crystal structures of Pd(bpy-κ2N)(η2-pbq) (1) Pd(dafo-κN)(η2-nq)2 (14) and Pd2(μ2-dafo)(μ2,η2:η2-pbq)2 (16) have been determined. Of the ligands, dafo and dafe are the only ones apt to form complexes containing a monodentate or bridging N∩N ligand. This behaviour is ascribed to the geometrical constraints of dafo and dafe; the annelation by one carbon atom at the 3,3′-positions in these ligands causes an increase in bite angle from approximately 77° to 82°.
Type of Medium:
Electronic Resource
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