Dennis A. Edwards

The synthesis and spectral features of some cationic manganese(I) and rhenium(I) tricarbonyl complexes

Abstract More than twenty cationic manganese or rhenium tricarbonyl complexes of the types fac-[M(CO)3L3]ClO4 (L = C5H5N or ethylenethiourea; L3 = tri-2pyridylamine, diethylenetriamine or E-pyridine-2-carbaldehyde-2′-pyridylhydrazone), fac-[M(CO)3X2Y]ClO4 (X2 = 2 C5H5N, 2,2′-bipyridyl, di-2-pyridylamine, 2 PPh3, Ph2PCH2PPh2, Ph2PCH2CH2PPh2, Ph2PCH2CH2AsPh2, or Ph2AsCH2CH2AsPh2; Y = MeCN), or fac-[M(CO)3XY2]Cl04 (X = AsPh3; Y= MeCN) have been prepared by displacement of acetonitrile groups from fac-[M(CO)3(NCMe)3]ClO4. The dicarbonyl cationic complex [Mn(CO)2(PPh3)2(NCMe)2]ClO4 has also been synthesised. The compounds have been characterised by conductivity measurements, and by infrared (4000-40 cm−) and 1H and 31P NMR spectroscopy. Trends in Cotton-Kraihanzel CO stretching parameters are discussed.

Aerosol-assisted chemical vapour deposition (AACVD) of silver films from triorganophosphine adducts of silver carboxylates, including the structure of [Ag(O2CC3F7)(PPh3)(2)]

Abstract Silver carboxylates [Ag(O 2 CR): R=Me, t Bu, 2,4,6-Me 3 C 6 H 2 ], fluorocarboxlyates [Ag(O 2 CR f ): R f =C 3 F 7 , C 6 F 13 , C 7 F 15 ] and their phosphine adducts [Ag(O 2 CR)· n PR 3 ′: R=Me, t Bu, 2,4,6-Me 3 C 6 H 2 , R′=Me, Ph, n =2; R=Me, R′=Me, n =3; Ag(O 2 CR f ).2PPh 3 , R f =C 3 F 7 , C 6 F 13 , C 7 F 15 ] have been synthesised, characterised spectroscopically and used as precursors in the aerosol-assisted chemical vapour deposition of silver films. All the phosphine adducts produced films, though in general PMe 3 adducts, proved more successful than PPh 3 analogues. The fluoro-carboxylates and their PPh 3 adducts all generated silver films, though the growth rate for the adducts was lower. All these latter films showed carbon impurities while fluorine was also evident in most cases. The X-ray structure of AgO 2 CC 3 F 7 ·2PPh 3 is also reported.

Aerosol-assisted chemical vapour deposition (AACVD) of silver films from triphenylphosphine adducts of silver β-diketonates and β-diketoiminates, including the structure of [Ag(hfac)(PPh3)]

Triphenylphosphine adducts of silver β-diketonates [AgL(PPh 3 )] (L=acac, dpm, tfac, hfac, fod) and β-ketoiminates (L=hfacNhex, hfacNchex) have been synthesised and evaluated as precursors for the deposition of silver films using aerosol-assisted chemical vapour deposition methodology. The 1:1 stoichiometry of the adducts has been established by 31 P and 109 Ag NMR and a crystal structure of [Ag(hfac)(PPh 3 )]. The best films were obtained from the two β-ketoiminates, particularly L=hfacNhex. While [AgL(PPh 3 )] (L=acac, dpm) gave almost no deposition, the complex with L=tfac gave a film comparable with the two β-ketoiminates while other films showed poor reflectivity (L=hfac, fod).

Some complexes derived from zinc salicylate or 3,5-di-tert-butylsalicylate. The crystal structure of (2,2′-bipyridyl)(methanol)(O-salicylato)(O,O′-salicylato)zinc

Abstract The aqua ligands of diaquabis(salicylato)zinc and diaquabis(3,5-di-tert-butylsalicylato)zinc are easily displaced generating related bis-pyridine and 2,2′-bipyridyl complexes. Attempts to recrystallise the tert-butylsalicylate from ethanol resulted in replacement of the aqua ligands by ethanol ligands. The attempted recrystallisation of (2,2′-bipyridyl)bis(salicylato)zinc from methanol led to the isolation of octahedral [Zn(O2CC6H4OH-2)2(bipy)(MeOH)] in which one salicylato ligand is coordinated in a monodentate fashion and the other in a bidentate chelating manner, both coordination modes involving carboxylate rather than hydroxyl oxygen coordination. The methanol is strongly bonded trans to a nitrogen of the chelating 2,2′-bipyridyl and three further intramolecular six-membered hydrogen bonded rings are present, generated from interactions between the carboxyl and hydroxyl groups of the salicylate ligands and the hydroxyl group of the methanol ligand.

Aerosol-assisted chemical vapour deposition of silver films from adducts of functionalised silver carboxylates

A series of silver carboxylates containing unsaturated groups within the ligand have been synthesised [AgO2CR, R = CH2CN (1), H2CCH (3), H2CCHCH2CH2 (5), Me(H)CC(Me) (8), Ph(H)CCH (11)], along with their triphenylphosphine [AgO2CR(PPh3)2, R = CH2CN (2), H2CCH (4), H2CCHCH2CH2 (6), Me(H)CC(Me) (9), Ph(H)CCH (12)] and 1,2-bis(phenylthio)ethane adducts [AgO2CR(PhSCH2CH2SPh)2, R = H2CCHCH2CH2 (7), Me(H)CC(Me) (10)]. The structures of 2, 6, 8 and 9 have been determined by single crystal X-ray diffraction; the adducts are all four-coordinate at silver with a chelating carboxylate, while 8 adopts a polymeric structure based on dimeric units and in which an approximately octahedral geometry at silver is attained by additional weak intermolecular Ag⋯O and π-Ag⋯CC interactions. Silver films have been grown by aerosol-assisted chemical vapour deposition using 6, 7, 9 and 10; no film was obtained with 2, while only a very thin film was generated by 12. Films grown from the sulfur-containing adducts 7 and 10 were rough and poorly reflective, while films from 6 and 9 were of superior quality, being smooth and highly reflective.

Silver(I) carboxylates. I. Mass spectra and low frequency infrared spectra

The mass spectra six silver(I) carboxylates, AgO2CR, (R = Me, Et, Prn, Ph, CF3 and (CF2)2CF3) show these compounds to be dimeric in the vapour phase, the base peak being the ion Ag2(O2CR)+ in each case. Two fragmentation pathways are observed. The alkyl carboxylates initially lose mainly RCO2· from the radical ion Ag2O2CR)2+, whereas the benzoate and the perfluorocarboxylates also easily lose carbon dioxide from the radical ion leading to the formation of abundant organosilver ions. The low frequency (500−40 cm−1) infrared spectra of these silver(I) carboxylates are compared with the spectra of the copper(I) analogues and bands selected which may be assigned to predominantly skeletal modes.

Some aspects of the coordination chemistry of 2-pyridinecarbaldehyde azine, (2-paa). The crystal structure of a complex with manganese(II), cis-[MnCl2(2-paa)2]

Abstract In the complex cis-[MnCl2(2-paa)2], (2-paa = 2-pyridinecarbaldehyde azine) each 2-paa behaves as a bidentate chelating ligand using adjacent pyridyl and azine nitrogen donor atoms. Twisting about the NN bonds removes the remaining two nitrogen donor atoms of each 2-paa away from the vicinity of the metal centre. This complex is the first to be reported containing two bidentate 2-paa ligands. Only one previous example of a metal complex involving a single bidentate 6-methyl-2-paa ligand has been examined structurally. The complexes [Mn2Cl4(2-paa)], [Zn2(NO3)4(2-paa)] · 2H2O and [Ag2(NO3)2(2-paa)] have also been isolated, NMR evidence indicating that in the zinc and silver complexes the 2-paa ligands act in a double bidentate coordination mode.

Anionic tricarbonyl derivatives of molybdenum and tungsten and their reactions with allyl halides

A series of carbonylmetallate anions fac-[MX(CO)3L2]−, where M = Mo or W, X = Cl, Br or I and L2 = 1,10-phenanthroline(phen) or 2,2′-bipyridine(bipy) have been prepared from the corresponding cis-M(CO)4L2 complexes. No evidence of fac-to mer-isomerisation was evident on dissolution, although in MeCN solvolysis occurred with the formation of fac-M(CO)3L2(MeCN). Reaction of the anions with various allyl halides resulted in high yields of η3-allyl complexes [MX(CO)2(η3-RC3H4)L2]. The significance of these observations for the mechanism of the allyl oxidative-addition reaction are discussed.

The preparation and characterisation of tri-μ -halogenohexacarbonyl-dimetallate(I) anions of manganese and rhenium

Abstract The final products of the reactions between Mn(CO) 5 X and Et 4 NX (X  Cl or Br) in boiling chloroform and between Re(CO) 5 X and Et 4 NX (X  Cl, Br or I) in boiling decalin are the compounds Et 4 N[M 2 (CO) 6 (μ-X) 3 ]. Vibrational spectroscopic results indicate that the anions possess bi-confacial octahedral geometry with three bridging halogen atoms.

Cationic copper(I) isocyanide complexes, [Cu(CNR)4]+ (R = CH3, C(CH3)3 and 2,6-(CH3)2C6H3): Preparations, spectroscopic properties and reactions with neutral ligands. A comparison of the vibrational spectra of [Cu(CNCH3)4]+, [Cu(NCCH3)4]+ and [Cu(NCCD3)4]+

The copper(I) isocyanide complexes [Cu(CNR)4]X (R = Me, CMe3, or xylyl; X = PF6− or ClO4−) have been prepared and characterized using IR, Raman and 1H NMR spectroscopy. Subsequent reactions with neutral chelating ligands have afforded the pseudotetrahedral complexes [Cu(CNMe)2(bipy)]PF6, [Cu(CN-t-Bu)2L2]PF6 (L2 = bipy, phen, DAB, or dppe) and [Cu(CNxylyl)2(2,9-Me2phen)]PF6, (bipy = 2,2′-bipyridyl, phen = 1,10-phenanthroline, DAB = N,N′-di-tert-butylethylenediimine, and dppe = 1,2-bis(diphenylphosphino)ethane). A detailed study of the vibrational spectra of the related species [Cu(CNMe)4]ClO4, [Cu(NCMe)4]ClO4 and [Cu(NCCD3)4]ClO4 has also been carried out and assignments proposed. The acetonitrile ligands of [CU(NCMe)4ClO4 are easily replaced by other Group V donor ligands, the complexes [CuL4]ClO4 (L = PPh3, AsPh3, or SbPh3) having been isolated.