Iwona B. Szymańska

X-Ray crystal structure of [Ag4(μ-dppm)2(μ-C2F5COO)4]. Synthesis and spectroscopy of silver(I) perfluorinated carboxylate complexes with bis(diphenylphosphino)methane

Complexes of Ag(I) carboxylates with dppm = bis(diphenylphosphino)methane of general formula [Ag2(RCOO)2(dppm)], where R = CF3, C2F5, C3F7, C4F9, C6F13, C9F19, were obtained and characterized with 1H, 13C, 19F, 31P NMR and IR. The X-ray crystal structure of [Ag4(μ-dppm)2(μ-C2F5COO)4] determined at 100(1) K (R = 0.0316) revealed a centrosymmetric tetranuclear aggregate with the silver atoms bridged by two dppm and four pentafluoropropionates forming two monoatomic μ2-(η1-O) and two triple μ3-(η2-O, η1-O′) bridges. Of the two crystallographically independent Ag(I) atoms one has distorted tetrahedral geometry with one Ag–P bond and three Ag–O bonds, while the second has trigonal planar geometry with an Ag–P and two Ag–O bonds. The 31P CP MAS NMR spectra demonstrate splitting due to 1J(107,109Ag–31P) and 2J(P–P) coupling between crystallographically inequivalent phosphorus atoms. Variable-temperature 31P NMR spectra were recorded between 323 and 223 K and 1J(107Ag–31P), 3J(107Ag–31P), 1J(109Ag–31P), 3J(109Ag–31P) spin–spin coupling constants calculated. Analysis of coordination shifts and coupling constants is in favor, in solution, of binuclear trigonal Ag(I) complexes with bridging carboxylates and dppm.

VARIABLE-TEMPERATURE 31P AND 63Cu NMR AND MASS SPECTROSCOPIC CHARACTERISATION OF NEW COPPER(I) PERFLUORINATED CARBOXYLATE COMPLEXES WITH 1,2-BIS(DIPHENYLPHOSPHINE)ETHANE

Abstract Copper(I) perfluorinated carboxylates complexes with 1,2-bis(diphenylphosphine)ethane (dppe) of general formula [Cu2(dppe)2(μ—RCOO)2] and [Cu(dppe)2](RCOO) R = C2F5, C4F9, C6F13 have been prepared and characterised by vibrational and mass spectra in the solid state and with 13C, 19F NMR and variable temperature 31P, 63Cu NMR spectra in solution. Monomeric forms can be proposed for complexes with M: L = 1:2, and dimeric for M : L = 1:1. Temperature variable 31P NMR spectra revealed the species [Cu2(dppe)2(μ—RCOO)2], [Cu2(dppe)2 (RCOO)]+, [Cu(RCOO)(dppe)], [Cu(dppe)2]+ in equilibrium. Analysis of IR and mass spectra suggests bridging carboxylates in [Cu2(dppe)2(μ-RCOO)2] and ions in [Cu(dppe)2(RCOO).

Electron interaction with copper(II) carboxylate compounds

In the present study we have performed electron collision experiments with copper carboxylate complexes: [Cu2(t-BuNH2)2(µ-O2CC2F5)4], [Cu2(s-BuNH2)2(µ-O2CC2F5)4], [Cu2(EtNH2)2(µ-O2CC2F5)4], and [Cu2(µ-O2CC2F5)4]. Mass spectrometry was used to identify the fragmentation pattern of the coordination compounds produced in crossed electron – molecular beam experiments and to measure the dependence of ion yields of positive and negative ions on the electron energy. The dissociation pattern of positive ions contains a sequential loss of both the carboxylate ligands and/or the amine ligands from the complexes. Moreover, the fragmentation of the ligands themselves is visible in the mass spectrum below m/z 140. For the studied complexes the metallated ions containing both ligands, e.g., Cu2(O2CC2F5)(RNH2)+, Cu2(O2CC2F5)3(RNH2)2 + confirm the evaporation of whole complex molecules. A significant production of Cu+ ion was observed only for [Cu2(µ-O2CC2F5)4], a weak yield was detected for [Cu2(EtNH2)2(µ-O2CC2F5)4] as well. The dissociative electron attachment processes leading to formation of negative ions are similar for all investigated molecules as the highest unoccupied molecular orbital of the studied complexes has Cu–N and Cu–O antibonding character. For all complexes, formation of the Cu2(O2CC2F5)4 −• anion is observed together with mononuclear DEA fragments Cu(O2CC2F5)3 −, Cu(O2CC2F5)2 − and Cu(O2CC2F5)−•. All dominant DEA fragments of these complexes are formed through single particle resonant processes close to 0 eV.

(Penta­fluoro­propionato-κO)tetra­kis­(trimethyl­phosphine oxide-κO)copper(II) penta­fluoro­propionate

The title compound, [Cu(C3F5O2)(C3H9OP)4](C3F5O2), comprises a cationic CuII complex and a disordered pentafluoropropionate counter-ion. The metal atom has a distorted square-pyramidal coordination environment formed by four O atoms originating from trimethylphosphine oxide molecules and the remaining one belonging to the monodentate pentafluoropropionate anion, which is situated in the basal plane of the pyramid. The molecules are held together in the crystal by a net of weak C—H⋯O and C—H⋯F hydrogen bonds. The counter anion is disordered over two sets of sites in a 0.629 (5):0.371 (5) ratio.