title: Metallophilic bonding and agostic interactions in gold(I) and silver(I) complexes bearing a thiotetrazole unit.
abstract: Gold(I) and silver(I) complexes of 1-methyl-5-thio-tetrazole (1) have been prepared and the coordination chemistry of this ligand toward metal-phosphine frameworks has been explored. As indicated by IR and Raman data, ligand 1 is deprotonated and the resulted anion acts as a bidentate (S,N)-tetrazole-5-thiolato unit in the new gold(I) complexes, [Au(SCN(4)Me)(PPh(3))] (2), [{Au(SCN(4)Me)}(2)(μ-dppm)] (3), and [{Au(SCN(4)Me)}(2)(μ-dppe)] (4), while it is coordinated only through the sulfur atom as its neutral tetrazole-5-thione form in the silver(I) derivative, [Ag(HSCN(4)Me)(PPh(3))](2)(OTf)(2) (5). Further characterization of the new compounds was performed using multinuclear ((1)H, (13)C, (31)P, (19)F) NMR spectroscopy, mass spectrometry, and DSC measurements. Single-crystal X-ray diffraction studies revealed basically linear P-M-S arrangements in complexes 3-5. The bidentate (S,N) coordination pattern results in a T-shaped (S,N)PAu core in 3 and 4, whereas, in 5, a similar coordination geometry is achieved in the dimer association based on S-bridging ligand 1. Herein, weak (C)H···Au and (C)H···Ag agostic interactions were observed. An intramolecular Au···Au contact occurs in 3, while in 4 intermolecular aurophilic bonds lead to formation of a chain polymer. An intermolecular Ag···Ag contact is also present in the dimer unit of 5. Low-temperature (31)P NMR data for 5 evidenced the presence of monomer and dimer units in solution. Theoretical calculations on model of the complexes 2 and 4 are consistent with the geometries found by X-ray diffraction studies.
authors.affiliation: Department of Chemistry, Ludwig-Maximilians-University Butenandtstrasse. 5-13 (Haus D), Munich, D-81377, Grosshadern, Germany.
authors.forename: Adriana
authors.initials: A
authors.lastname: Ilie
authors.forename: Ciprian I
authors.initials: CI
authors.lastname: Raţ
authors.forename: Susanne
authors.initials: S
authors.lastname: Scheutzow
authors.forename: Christiane
authors.initials: C
authors.lastname: Kiske
authors.forename: Karin
authors.initials: K
authors.lastname: Lux
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Klapötke
authors.forename: Cristian
authors.initials: C
authors.lastname: Silvestru
authors.forename: Konstantin
authors.initials: K
authors.lastname: Karaghiosoff
mesh_terms: D018360:Crystallography, X-Ray; D006046:Gold / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013777:Tetrazoles / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D013777:Tetrazoles; C038625:1-N-methyl-5-thiotetrazole; D012834:Silver; D006046:Gold