Synthesis of [{AgO(2)CCH(2)OMe(PPh(3))}(n)] and theoretical study of its use in focused electron beam induced deposition

The synthesis, chemical and physical properties of [{AgO(2)CCH(2)OMe}(n)] (1) and [{AgO(2)CCH(2)OMe(PPh(3))}(n)] (2) are reported. Consecutive reaction of AgNO(3) with HO(2)CCH(2)OMe gave 1, which upon treatment with PPh(3) 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 PPh(3)–Ag(I) coordinative bonds results in distorted T-shaped AgPO(2) 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 [AgO(2)CCH(2)OMe(PPh(3))]. At an energy of the secondary electrons up to 0.8 eV elimination of PPh(3) occurs, giving Ag(+) and O(2)CCH(2)OMe(−). Likewise, by release of PPh(3) from [AgO(2)CCH(2)OMe(PPh(3))] the fragment [AgO(2)CCH(2)OMe](−) is formed from which Ag(+) and O(2)CCH(2)OMe(−) is generated, further following the first fragmentation route. However, at 1.3 eV the initial step is decarboxylation giving [AgCH(2)OMe(PPh(3))], followed by Ag–P and Ag–C bond cleavages.