The synthesis of some aminobis(methylphosphines) and their transition metal complexes.

Chapter 1 reviews the literature concerning the synthesis of aminomethylphosphines together with the analogous ditertiary phosphines. Macrocyclic aminomethylphosphines and some water soluble phosphines are also reviewed together with a brief review of some metal complexes. The preparation and characterisation of the aminobis(methylphosphines) are presented in Chapter 2. Treatment of the phosphonium salts [R2P(CH2OH)2]C1 (R= Cy, Ph) with primary amines in the presence of triethylamine produced aminobis(methylphosphines) of the type (R2PCH2)2NR' where R= Cy, Ph and R'= Me, [-(CH2)nSO3][Et3NH] (n= 1, 2, 3). In addition to the above method, an ethylenediamine diacetate functionalised phosphine and a benzo-15-crown-5 functionalised aminobis(methylphosphines) have also been obtained by treating Ph2PH with aqueous formaldehyde in the presence of the relevant primary amine in toluene. The phosphines (Cy2PCH2)2NMe and [(Ph2PCH2)2NCH2CH2SO3] [Et3NH] have been characterised by single crystal X-ray structure determinations. In Chapter 3 a variety of transition metal complexes have been obtained using aminobis (methylphosphines) prepared in Chapter 2. The metal complexes have been characterised using spectroscopic techniques and microanalytical data. All the complexes are cis mononuclear except the rhodium complex of [(Ph2PCH2)2N(CH2)2SO3][Et3NH], (dppaes) which has a trigonal bipyramidal geometry. The single crystal X-ray structure determinations of the platinum, palladium and nickel complexes of the phosphines (R2PCH2)2NMe (R= Cy, dcpam; Ph, dppam) show the phosphines in a six-membered chelate chair conformation. Treatment of platinum complexes of dcpam and dppam with silver acetate and silver carbonate in dichloromethane afforded novel acetate and carbonate derivatives respectively. Treatment of both carbonate and dichloride derivatives of platinum (II) phosphine complexes with 2-mercapto imidazole gave four membered platinacycle complexes. Treatment of [PtCl2(L)] (L= dcpam, COD, dppp) with two or three mole excess of 2-acetamidoacrylic acid in the presence of silver oxide produced carbon-oxygen bonded isomers rather than nitrogen-oxygen bonded isomers. Some reactions of the metal dichloride complexes with Nal, tBuNC, PPh3, HCl, CF3SO3Me have also been investigated. The last Chapter investigates the synthesis, characterisations and some reactions of zerovalent platinum and palladium aminobis (methylphosphine) complexes of the type [M(dba)(P-P)] (M= Pt, Pd; P-P= dcpam, dppam). The complexes have been characterised by means of spectroscopic and microanalytical data. The complex [Pd(dba)(dcpam)] has also been characterised by a single crystal X-ray structure determination. The platinum complex [Pt(dba)(dcpam)] does not react with carbon monoxide, dmad or diphenylacetylene. However, the dba ligand in the corresponding palladium complex is displaced by dmad and fumaronitrile. A zerovalent mixed phosphine-platinum complex has been prepared by reducing either [PtCl2(dcpam)] with hydrazine hydrate in ethanol followed by addition of triphenylphosphine or reducing [PtCl2(PPh3)2] followed by addition of dcpam to give [Pt(dcpam)((PPh3)]. Treatment of [Pt(dcpam)((PPh3)] with allylchloride or mercury chloride in dichloromethane gave [PtCl2(dcpam)] whereas oxygen, carbon monoxide or acetic acid did not react with the zerovalent complex.