Peter Frenzel

Crystal structure of cyclo-bis­(μ4-2,2-di­allyl­malonato-κ6O1,O3:O3:O1′,O3′:O1′)tetra­kis­(triphenyl­phosphane-κP)tetra­silver(I)

In the title compound, the silver(I) ions are coordinated by four triphenylphosphane ligands and two 2,2-diallylmalonate anions in a μ4-(κ6 O 1,O 3:O 3:O 1′,O 3′:O 1′) mode, setting up an Ag4O8P4 core.

Synthesis of [{AgO2CCH2OMe(PPh3)}n] and theoretical study of its use in focused electron beam induced deposition

The synthesis, chemical and physical properties of [{AgO2CCH2OMe}n] (1) and [{AgO2CCH2OMe(PPh3)}n] (2) are reported. Consecutive reaction of AgNO3 with HO2CCH2OMe gave 1, which upon treatment with PPh3 produced 2. Coordination compound 2 forms a 1D coordination polymer in the solid state as evidenced by single crystal X-ray structure analysis. The coordination geometry at Ag+ is of the [3 + 1] type, whereby the carboxylate anions act as bridging ligands. The formation of PPh3–Ag(I) coordinative bonds results in distorted T-shaped AgPO2 units, which are stabilized further by an additional O–Ag dative bond. TG and TG–MS measurements show that 1 and 2 decompose at 190–250 °C (1) and 260–300 °C (2) via decarboxylation, involving Ag–P (2), C–C and C–O bond cleavages to give elemental silver as confirmed by PXRD studies. In order to verify if polymeric 2 is suitable as a FEBID precursor for silver deposition, its vapor pressure was determined (p 170 °C = 5.318 mbar, ∆H vap = 126.1 kJ mol−1), evincing little volatility. Also EI and ESI mass spectrometric studies were carried out. The dissociation of the silver(I) compound 2 under typical electron-driven FEBID conditions was studied by DFT (B3LYP) calculations on monomeric [AgO2CCH2OMe(PPh3)]. At an energy of the secondary electrons up to 0.8 eV elimination of PPh3 occurs, giving Ag+ and O2CCH2OMe−. Likewise, by release of PPh3 from [AgO2CCH2OMe(PPh3)] the fragment [AgO2CCH2OMe]− is formed from which Ag+ and O2CCH2OMe− is generated, further following the first fragmentation route. However, at 1.3 eV the initial step is decarboxylation giving [AgCH2OMe(PPh3)], followed by Ag–P and Ag–C bond cleavages.

Crystal structure of (μ-1,4-di-carb-oxy-butane-1,4-di-carboxyl-ato)bis-[bis-(tri-phenyl-phosphane)silver(I)] di-chloro-methane tris-olvate.

The molecular structure of the distorted trigonal–planar-coordinated tetrakis(triphenylphosphanyl)disilver salt of butane-1,1,4,4-tetracarboxylic acid is reported, present as a dichloromethane trisolvate. The coordination complex exhibits an inversion centre through the CH2—CH2 bond and intermolecular T-shaped π–π interactions between the phenyl rings of the PPh3 substituents, forming a ladder-type superstructure parallel to the b axis.

Crystal structure of an unknown tetra­hydro­furan solvate of tetra­kis­(μ3-cyanato-κ3N:N:N)tetra­kis­[(triphenyl­phosphane-κP)­silver(I)]

In the title compound a distorted Ag4N4-heterocubane core is set up by AgI cations and N atoms of cyanate anions. The core is decorated by four triphenylphosphine ligands bonded to the AgI cations. Ag⋯Ag distances as short as 3.133 (9) Å suggest the presence of argentophilic (d 10⋯d 10) interactions.