Add time:07/28/2019         Source:sciencedirect.com

The absorption spectra of acetylene and acetylene-d2 have been photographed at high dispersion in the 1280 to 1520A region. The vibrational structure of two Rydberg transitions at 65814 cm−1 (3R-A) and 74498 cm−1 (3R′-A) previously reported by Price has been analyzed. Both of these transitions possess simple vibrational structure composed of only totally symmetric vibrations and must, therefore, be linear or very nearly so. However, a third transition (C-A) involving a trans-bent upper state has been found at 74747 cm−1 and, in addition, a fourth transition (B-A) at 74622 cm−1 involving a trans-bent and twisted upper state has been identified.The vibration identified in state 3R is (C2H2): ν2(σg) = 1849 cm−1; (C2D2): ν2(σg) = 1720 cm−1. Those in state 3R′ are 3R′ are (C2H2) ν1(σg) = 2748 cm−1, ν2(σg) = 1781 cm−1 and ν4(πg) = 393 cm−1; (C2D2); ν1(σg) = 2053 cm−1, ν2(σg) = 1559 cm−1 and ν4(πg) = 302 cm−1. The four vibrations identified in state B are (C2H2): ν1(ag) = 2808 cm−1 ν2(ag) = 1500 cm−1, ν3(ag) = 759 cm−1 and ν5(au) = 630 cm−1; (C2D2): ν1(ag) = 2303 cm−1, ν2(ag) = 1342 cm−1, ν3(ag) = 635 cm−1 and ν5(au) = 438 cm−1. The ν4(bu) vibration has also been tentatively identified with magnitudes ∼1880 cm−1 (C2H2) and ∼1100 cm−1 (C2D2). In state C two vibrations are identified with magnitudes (C2H2): ν2(ag) = 1751 cm−1, ν3(ag) = 434 cm−1; (C2D2): ν2(ag) = 1542 cm−1, ν3(ag) = 365 cm−1.The moment of inertia Ix is small in both B and C states causing sub-band separations of 10 to 100 cm−1. The rotational constants are: B ∼ C ∼ 1 cm−1. A ∼ 7 cm−1 (C2D2) and ∼ 8 cm−1 (C2H2) in both bent upper states. Vibrational data are given for all of the observed transitions.The identification of the observed states with some of those predicted by Mulliken is open to criticism. However, it is suggested that state C is Mulliken's 1Aa, predicted to lie at 8.63 ev and state B is Mulliken's 1Bu(Vπ) which interacts with 3R′ causing some nonlinearity in the latter.

We also recommend Trading Suppliers and Manufacturers of ACETYLENE-D2 (cas 1070-74-2). Pls Click Website Link as below: cas 1070-74-2 suppliers