Structural Studies Of Metal Phosphine Complexes

Author : Hau-San Tang
Publisher : Open Dissertation Press
ISBN 13 : 9781361426982
Total Pages : pages
Book Rating : 4.4/5 (269 download)

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Download or read book Design and Synthesis of Metal Phosphine Complexes of Palladium(ii) and Gold(i) with Various Receptor Ligands for Ion-Controlled Or Photoresponsive Host-Guest Chemistry written by Hau-San Tang and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Design and Synthesis of Metal Phosphine Complexes of Palladium(II) and Gold(I) With Various Receptor Ligands for Ion-controlled or Photoresponsive Host-guest Chemistry" by Hau-san, Tang, 鄧巧珊, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled DESIGN AND SYNTHESIS OF METAL PHOSPHINE COMPLEXES OF PALLADIUM(II) AND GOLD(I) WITH VARIOUS RECEPTOR LIGANDS FOR ION-CONTROLLED OR PHOTORESPONSIVE HOST-GUEST CHEMISTRY Submitted by Tang Hau San for the Degree of Doctor of Philosophy at The University of Hong Kong in August 2006 A series of palladium(II) phosphine complexes containing different receptor sites, [Pd(PPh R) Cl] [R = C H NHCOCH, C H N(CH )COCH, 2 2 2 6 4 3 6 4 3 3 C HNHCONHPh, C HNHCOPyr and C H NHCO(CH )Pyr] have been 6 4 6 4 6 4 2 3 prepared. Two X-ray crystal structures have been determined, in which one of the crystal structures showed hydrogen bonding interactions between the amide protons and the Cl ions with distances of ca. 2.466 A. The photophysical properties of these complexes have been studied and their emission origins were elucidated. The binding properties of the complexes towards anions have 1 31 been studied by H NMR, P NMR, UV-vis and emission spectrophotometry, in which drastic changes in the ratio of trans to cis isomers upon addition of 31 anions were observed in the P NMR titration studies. The present ion-induced conformational change involving a trans-cis isomerization of the square-planar palladium(II) complex via the binding of anions to amide or urea functionalities through hydrogen bonding interactions represents a new class of ion-controlled switching devices based on transition metal systems. A series of gold(I) alkynyl phosphine complexes containing azobenzene or stilbene functionalities, [{Au(PPh )} (C≡C-L-C≡C)] and [Au (P DEGREESP) (C≡C-L- 3 2 4 2 C≡C) ] [L = C H -N=N-C H or C H -CH=CH-C H; P DEGREESP = dppm, dcpm, 2 6 4 6 4 6 4 6 4 Ph PN(C H F-p)PPh, Ph PN( Pr)PPh, Ph PN(C H )PPh] have been 2 6 4 2 2 2 2 14 29 2 synthesized and characterized. The X-ray crystal structure of [Au (dppm) (C≡C- 4 2 L-C≡C) ] revealed that the two azobenzene ligands in the tetranuclear complex adopted a trans disposition with the presence of short intramolecular Au Au contacts. The azobenzene-containing gold(I) complexes showed emissions both in dichloromethane solution at room temperature and in 77 K glass, which were assigned as a metal-perturbed intraligand (IL) origin mainly derived from the π-π*(C≡C) states with some mixing of a π-π* character of the azo unit. On the other hand, the emissive origin of the stilbene-containing gold(I) complexes was assigned as derived from the π-π* excited state of the stilbene moiety with some mixing of the alkynyl units, and probably mixed with σ(Au-P) → π*(C≡C) excited state in the solid states. The photoisomerization properties of the dinuclear and tetranuclear complexes have been studied, in which a tetranuclear macrocyclic gold(I) alkynyl phosphine complex was demonstrated to function as a dual input molecular logic with photoswitching behaviour that could be controlled by addition or removal of silver(I). In addition, several gold(I) complexes with different crown ether pendants including the mercapto-azacrown ether-containing complexes, [Au (P DEGREESP)(S-A15C5) ] [P DEGREESP = dppm, dcpm] and the mononuclear gold(I) alkynyl 2 2 complexes, [Au(PPh )(C≡CR)] [R = B15C5, B15S5], and dinuclear gold(I) complexes with oligo(ethylene oxide) linkages, [{(Ph P)