FTIR Identification of the ν₄(σ_u) and ν₆(π_u) Modes of Linear GeC₃Ge Trapped in Solid Ar

Abstract

GeC 3Ge was previously (1) produced by the dual laser ablation of germanium and carbon rods, and the nu 3(sigma u) carbon-carbon stretching fundamental was assigned at 1920.7 cm (-1). This paper presents results from new experiments that have enhanced the production of the molecule via laser ablation of a single sintered germanium-carbon rod, thus enabling the identification of two additional infrared active vibrational fundamentals. Ge participates strongly in one of these, the nu 4(sigma u) mode, and the corresponding Ge isotopic shifts reported here are the first for a germanium-carbon species. GeC 3Ge was produced by trapping the products from the laser evaporation of the Ge-C rod, in solid Ar at approximately 10 K, and recording the FTIR (Fourier transform infrared) spectra. Comparison of (70,72,73,74,76)Ge and (13)C isotopic shift measurements with the predictions of density functional theory calculations (DFT) at the B3LYP/cc-pVDZ level confirms the identification of the nu 4(sigma u) stretching fundamental at 735.3 cm (-1) and the nu 6(pi u) bending fundamental at 580.1 cm (-1) for linear GeC 3Ge.

Structural, electronic and vibrational properties of Ge x C y ( x + y =2–5) nanoclusters: A B3LYP-DFT study

“…The higher frequencies 2016, 1519 belongs to the asymmetric and symmetric stretching of C-C-C configurations and other frequencies are obtained due to symmetric, asymmetric and bending mode of vibrations. The present calculated frequencies are also in good agreement with other workers [20,27,28]. Our predicted IR is also good agreement with others values [27,28].…”

“…The present calculated frequencies are also in good agreement with other workers [20,27,28]. Our predicted IR is also good agreement with others values [27,28].…”

“…The pentagonal (6G) structure possesses one imaginary frequency and therefore is unstable. Ge 2 C 3 : The linear GeCCCGe (7B) structure possess highest frequency 2016 cm À 1 which 5% higher than the experimental value 1920.7 cm À 1 observed by Robbins et al [27] and the frequency 740 cm À 1 is in excellent agreement with experimentally observed frequency 736 cm À 1 [28]. The higher frequencies 2016, 1519 belongs to the asymmetric and symmetric stretching of C-C-C configurations and other frequencies are obtained due to symmetric, asymmetric and bending mode of vibrations.…”

“…The vibrational spectra of germanium-carbon cluster GeC 3 [26], GeC 3 Ge [27,28], GeC 7 , GeC 9 [29], GeC 5 Ge [30] have been studied experimentally and theoretically.…”

Infrared observation of linear GeC3 trapped in solid Ar

“…From a series of experiments testing different ratios, it was concluded that a mass ratio of Ge: C = 0.45: 1 was optimum, in contrast to Ge: C = 1.5: 1 for GeC 3 Ge. 21 The evaporation of germanium and carbon was carried out using two neodymium doped yttrium aluminum garnet lasers ͑Spectra Physics͒ operating at 1064 nm in the pulse mode. The evaporated species were condensed in solid Ar ͑Matheson, 99.9995% purity͒ on a gold surfaced mirror cooled to ϳ10 K by the closed-cycle refrigeration system ͑ARS, Displex͒.…”