title: Structure and spectroscopic properties of gold(I) diselenophosph(in)ate complexes: a joint experimental and theoretical study.
abstract: The structure and optical properties of several polynuclear gold(I) species, namely, diselenophosphate [Au{μ-Se(2)P(OR)(2)}](2) complexes (R = (i)Pr, Et, (n)Pr) respectively numbered 1, 2, and 3 and number 4 [Au{μ-Se(2)P(CH(2))(2)Ph)(2)}](2), exhibiting interesting structural, absorption, and emission properties have been studied. The synthesis, full characterization, and experimental spectroscopic study of 3 and 4 have first been carried out, 1 and 2 being previously studied. In the solid state, 3 gives polymers, like 1 and 2, whereas 4 exists under a dinuclear monomeric form. The absorption and phosphorescence properties of 4 have been rationalized using DFT and TDDFT computations. In particular, Au-Au bonding seems to appear in its first singlet and triplet states, whereas such a bond does not exist in the ground state. Then, the influence of polymerization through aurophilic bonding on the optical properties of 2 is investigated (1 and 3 behave as 2). It is shown using TDDFT computations that its observed UV-visible excitation spectrum in solution is due to high oligomers and not to monomers or low size oligomers. ESI-MS molecular weight measurements confirm the occurrence of such oligomers of 2 in solution. An assignment of the observed bands of 2 is proposed. The transition corresponding to the first excitation band, which is mainly a HOMO to LUMO one, exhibits metal-centered character, i.e., a gold 5d to 6p orbital transition, but concomitantly transfers significant electron density from gold to phosphorus atoms so that it is also a MLCT one.
authors.affiliation: Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, Campus de Beaulieu, 35042 Rennes cedex, France.
authors.forename: Camille
authors.initials: C
authors.lastname: Latouche
authors.forename: Yu-Chen
authors.initials: YC
authors.lastname: Lee
authors.forename: Jian-Hong
authors.initials: JH
authors.lastname: Liao
authors.forename: Eric
authors.initials: E
authors.lastname: Furet
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Saillard
authors.forename: C W
authors.initials: CW
authors.lastname: Liu
authors.forename: Abdou
authors.initials: A
authors.lastname: Boucekkine
mesh_terms: D018360:Crystallography, X-Ray; D008163:Luminescent Measurements; D008958:Models, Molecular; D050607:Organogold Compounds / Q000737:chemistry*; D010720:Phosphines / Q000737:chemistry*; D018036:Selenium Compounds / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet
chemical_list: D050607:Organogold Compounds; D010720:Phosphines; D018036:Selenium Compounds