Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.586053
Title: Synthetic and spectroscopic studies of some new organophosphorus (III) and (V) compounds
Author: Rusmidah, Ali
Awarding Body: Durham University
Current Institution: Durham University
Date of Award: 1987
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Abstract:
The acceptor properties of some halogenated organophosphorus (V) compounds towards chloride, pyridine, 2,2'-bipyridine and 1,10-phenanthroline have been investigated by means of 31p n.m.r. spectroscopy. It was found that C(_6)F(_5)PCl(_4) forms a six-coordinate anionic species C(_6)F(_5)PCl(_5)(^-) with R(_4)NCl which dissociates in solution. CCl(_3)PCl(_4) also show acceptor properties towards R(_4)NCl, but a stable adduct was only formed with Pr(_4)NCl in PhNO(_2), where no dissociation was observed. In CH(_2)Cl(_2), decomposition occurred in which CCl(_3)PCl(_2) was detected. In contrast, C(_2)Cl(_5)PCl(_4) only showed temporary formation of the adduct with Et(_4)NCl in CH(_2)Cl(_2), followed by decomposition, but it did not do so with R(_4)NCl (R=n-Pr, n-Bu or n-Pe) either in CH(_2)Cl(_2) or PhNO(_2), where only decomposition products were observed. As expected, the higher members of the series R(_4)PCl(_3) (R=C(_6)F(_5) or CCI(_3)) and (C(_6)F(_5))(_3)^PCl(_2) did not form adducts with R(_4)NCl, either in CH(_2)Cl(_2) or PhNO(_2). RPCl(_4) (R=C(_6)F(_5) or CCl(_3)) react with pyridine to give RPCl(_4).py, but no adduct was found with bidentate ligands (L). In contrast, the complexes [C(_2)Cl(_5)PCl(_3)L](^+)Cl(^-)were isolated. RPCl(_3)(^+)x(^-) (R=C(_6)F(_5) and CCl(_3); X=SbCl(_6) and BCl(_4)) also form adducts with L, giving six-coordinate cationic species [RPCl(_3)L](^+)X(^-) which exist in two isomeric forms in solution but only one isomer is dominant when the solid is isolated. The ionic compound [C(_6)F(_5)PBr(_3)][BBr(_4)] was isolated, but attempts to establish the chemical shift for the six-coordinate species with bidentate ligands L failed. Organophosphorus (111) halides (C(_6)F(_5)(_n)PCl(_3-n) (X=C1,Br, n=l, 2) and pseudohalides (C(_6)F(_5))(_n)PX(_3-n) (X=NCS, n=l;X=CN, n=2) show acceptor properties towards Y(^-) (Y=C1, Br, I and NCS) to form four-coordinate phosphoranides[(C(_6)F(_5))(_n)PX(_3-n)Y](^-), which all proved to be very unstable. Substitution reactions occurred with CN(^-) or NCS(^-) for (C(_6)F(_5))(_n)PX(_3-n) (X=C1, Br) and with CN(^-) for C(_6)F(_5)P(NCS)(_2). No acceptor properties were observed towards CI(^-), Br(^-), I(^-), CN(^-) or NCS(^-) ions for CCl(_3)PCl(_2) and (C(_6)F(_5)(_2)PNCS, whereas the compounds RP(NCS)(_2), (R=Me, Et or Ph) are thermally unstable and their Lewis acid behaviour could not be investigated. Substitution reactions occurred between AgNCS and RPCl(_3)(^+)x(^-) (R=Me or Ph, X=SbCl(_6); R=C(_6)F(_5), X=SbCl(_6) or BCl(_4)),giving [RPCl(_3-n)(NCS)(_n)](^+) (l
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.586053  DOI: Not available
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