Journal ArticleDOI
Comparison of 8-methylquinoline and benzo[h]quinoline complexes of palladium(II) with those of related ligands. Crystal and molecular structure of aqua(benzo[h]quinoline)[2-(dimethylaminomethyl)phenyl-N]palladium(II) perchlorate
TLDR
Benzo[h]quinoline (bquin) does not cleave the chloride bridge of [{Pd(dmp)Cl}2][dmp = 2-(dimethylaminomethyl)phenyl-N] as discussed by the authors.Abstract:
Benzo[h]quinoline (bquin) does not cleave the chloride bridge of [{Pd(dmp)Cl}2][dmp = 2-(dimethylaminomethyl)phenyl-N], 8-methylquinoline (8Me-quin) does so if in large excess, while other ligands L (pyridine, 2-methylpyridine, or 7-methylquinoline) give monomeric [Pd(dmp)Cl(L)] quantitatively. Measured equilibrium constants for the bridge-cleavage reaction indicate that the Pd⋯H–C interactions in bquin and 8Me-quin complexes are strongly destabilising. Rotations about the Pd–N bonds in [Pd(dmp)Cl(L)] are slow and no faster than equilibria involving dissociation to [{Pd(dmp)Cl}2]. Stable complexes of bquin and of 8Me-quin can, however, be readily formed if the strongly bridging chloride ligands are replaced by nitrate or perchlorate. For example, stoicheiometric addition of bquin to an acetone solution derived by addition of Ag[ClO4] to [{Pd(dmp)Cl}2] gives the title complex, [Pd(dmp)(bquin)(OH2)][ClO4], the crystal and molecular structure of which has been determined by single-crystal X-ray diffraction. The crystals are triclinic, a= 11.050(4), b= 9.808(4), c= 11.412(5)A, α= 77.04(4), β= 110.90(4), γ= 97.00(3)°, and Z= 2, space group P. The structure was solved by standard heavy-atom methods and refined by least squares, using 1976 observed data, to R 0.053. The co-ordination is essentially square planar with mutually trans nitrogen atoms. The most notable feature is the short H10(bquin)⋯Pd distance [2.09(6)A], but consistent with this being a non-bonding interaction is the ca. 10° tilt of the bquin (Pd–N–C 111 and 131°) in a direction that lessens this clash. From a comparison of 1,10-phenanthroline and other authentic bidentate ligands with 8Me-quin and bquin, it is concluded that the latter ligands are unidentate.read more
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The potential of palladacycles: more than just precatalysts
Journal ArticleDOI
The Difficulty of Coordinating Mutually trans Phosphine and Aryl Ligands in Palladium Complexes and Its Relation to Important Coupling Processes. Syntheses and Crystal Structures of a Family of Palladium Phosphino, Triflato, Perchlorato, and Aquo-2-(arylazo)aryl Complexes
TL;DR: In this article, the reaction between [Pd(C6H3NNR-2, X-5)Cl]2 and phosphines was shown to give a single crystal of 4a, 4b, 2a, 2c, or 3a.
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Cyclometallated complexes incorporating a heterocyclic donor atom; the interface of coordination chemistry and organometallic chemistry
TL;DR: In this paper, a general introduction to cyclometallated species is presented, followed by the synthesis of cyclometalated species and a mechanistic analysis of the resulting species.
Journal ArticleDOI
The chemistry of binuclear palladium(II) and platinum(II) complexes
Vimal K. Jain,Leela Jain +1 more
TL;DR: The chemistry of binuclear palladium(II) and platinum (II) complexes has been reviewed in this paper, which deals with complexes derived from various classes of ligands and covers various aspects, viz. synthesis, spectroscopic and structural features and chemical reactivity of these complexes.
Journal ArticleDOI
Palladium-Catalyzed Formylation of Aryl Bromides: Elucidation of the Catalytic Cycle of an Industrially Applied Coupling Reaction
TL;DR: Stoichiometric studies using the less efficient Pd/P(t)Bu3 catalyst resulted in the isolation and characterization of the first stable three-coordinated neutral acylpalladium complex, [Pd(Br)(p-CF3C6H4CO)(P( t)Bu 3)] (10).