The refinement of the crystal structure of norbornadiene palladium chloride

Abstract

The crystal structure of norbornadiene palladium chloride has been refined with data obtained by counter methods from crystals maintained at liquid nitrogen temperature. After refinement the conventional discrepancy index R = 0.0275. The carbon--carbon single bond distances in the norbornadiene molecule are normal: 1"547, 1.552, 1.554 (+ 0.006)/~; the double bond distances are barely significantly longer than normal: 1.366, 1.366 (+0.010) ~. The observed double bond distance is now compatible with the infrared spectrum of the complexed olefin.

The crystal and molecular structure of Zeise's salt, KPtCl3.C2H4.H2O

“…Similar results were obtained in the substituted acetylene complex [PtClz(ButC = CBut)(ptoluidine)] (Davies, Hewertson, Mais & Owston, 1967), where coordination reduces the C--C bond order by about ½, and the Pt-C bond [2.19(2) A] is also longer than expected for a single bond. These results differ from those of Baenziger, Doyle & Richards (1965) who found the C-C distance in the double bonds of norbornadiene palladium chloride to be barely significantly longer than in the uncomplexed olefin. It may be that olefins bond more strongly to platinum than to palladium.…”

The Crystal and Molecular Structure of Pentane-2,4-dionato-(2,3,5,6-tetrahepto-2,3-dicarbomethoxo[2.2.1]bicycloheptadiene)rhodium(I), Rh(C5H7O2) (C7H6(CO2CH3)2)

“…Within the norbornadiene group, all other distances agreed well with those found in free norbornadiene (14,15), a norbornadiene-palladium complex (16), and Rh-(hfac)py(NOR) ( I ) .~…”

“…This was despite the fact that, within a given compound, Rh-C distances for the two types of olefin group differed, that there was a marked change in the Rh-0 bond lengths, and that there was a change in geometry from pseudo-trigonal bipyramidal to pseudo-square planar. It was quite clear, after examining a number of structures (2,3,(16)(17)(18)(19)(20), that Rh-C distances were almost insensitive to geometry and could be predicted entirely on the basis of whether electron-withdrawing groups (e.g. F or C0,Me) were attached to the olefin or not.…”

Cyclopalladated Compounds with Polyhalogenated Benzylphosphanes for the Mizoroki‐Heck Reaction

“…To the best of our knowledge, the structure of 17a is the first one ever reported to contain a palladium coordinated to a metallated phosphane and a diene. In the reported structures of [PdCl 2 (nbd)] and [PdBr 2 (nbd)] the distances between the Pd and the diene are considerably shorter. In contrast, other structures containing the palladium embedded in a palladacyclopentadiene present similar Pd–nbd distances than in 17a .…”