The preparation and crystal structure analysis of some halo-mercury compounds

摘要

This thesis mainly deals with the synthesis and X-ray structure analysis of some halo-mercury compounds. In chapter 1, the published work on the structural chemistry of mercury compounds is described with special reference to the difficulties in determining a van der Waals radius for the metal. The different kinds of Hg6Cl13- interactions and the upper limit of an effective Hg5.5Cl13^2- interaction are discussed. In chapter 2, the preparation and structure determination of some compounds containing the anion Hg6Clt3- are described. The similarity of this anion to Hg5Cl11- and the anionic structure of "Hg5.5Cl11-" is discussed. Chapter 3 deals with the preparative experimental work of analysing the composition of the double salts of mercuric chloride with ethylenediamine chloride and with cobalt(III) ammonium chloride using the full-range solubility method. The resultant stoichiometries are described and discussed. Using the results obtained from chapter 3, two new ethylenediamine chloro-mercury salts, [NH3(CH2)2NH3]2[HgC14][Cl]2 and [{NH39CH2)2NH3][Hg2Cl6], were prepared and their X-ray single crystal structures were determined. One contains a [HgCl4^2-]n chain structure and the second contains [Hg2Cl6^2-] anions. Their structural characteristics are described and discussed. Chapter 5 deals with two cobalt(III) chloro-mercury salts of [Co(NH3)6][Hg3Cl9l]H20 and trans-[CoCl2(en)2]2[Hg2Cl6]. A new chloromercury anionic structure of [Hg3Cl9^Cl6] is found in the former and the latter contains the familar [Hg3Cl9^3-] anion. Their structural characteristics are described and related to the series of anionic structures of [Hg3Clx^n-] (X=9, 10, 12). The cation [H4trien] was investigated in the expectation that a new anion with four negative charges might result. The new compound of triethylenetetramine chloro-mercury, [H4trien][Hg2CL8], was prepared and its X-ray single crystal structure is described in chapter 6. It demonstrates the existence of the new anionic structure of [Hg2Cl8^4-], In order to assist in a study of the anation kinetics of [cis-PtCl2(NH3)2] with HgCl2, the X-ray single crystal structure of the adduct of HgCl2, the X-ray single with [cis-PtCl2(NH3)2] was determined and the correlation between this structure [cis-PtCl2(NH3)2(HgCl2)3] and related structures in the literature is illustrated in the chapter 7. In chapter 8, the major structural results of this project are summarized. The "structure-correlation approach method" is applied to the HgCl3- and Hg2CL6^2- structural subunits from our work and from the literature in order to determine the upper limit of an effective Hg···Cl interaction. An upper limit of 3.35Å is proposed, based on the analysis of currently available crystallographic data. Chapter 9 deals with two organomercury(II) complexes: [(Ph3P)CHCOPhHgCl2]CH3OH and [(Ph3P)CHCOPhHg[2], and their precursor ligand, [(Ph3P)CHCOPh]. Their X-ray single crystal structures are determined and their structural characteristics are described and discussed. These two organo-mercury compounds are examples in which the Hg atom adopts a distorted tetrahedral coordination geometry. They are also compared with related structures in the literature.