Laser-induced fluorescence and Optical/Stark spectroscopy of PtC

Abstract

Laser velocity modulation spectroscopy of the 3 Δ(3d4s)-X 3 Φ(3d 2 ) visible system of TiCl + and characterization of the spin-orbit structure Optical/Stark measurements have been performed on the ͑0,0͒ bands of both the AЉ 1 ⌺ ϩ -X 1 ⌺ ϩ system ( 0 Ϸ12 643 cm Ϫ1 ) and the AЈ 1 ⌸ -X ⌺ ϩ system ( 0 Ϸ13 196 cm Ϫ1 ) of platinum monocarbide. The PtC molecules were produced in a pulsed supersonic molecular beam source following the reaction of laser ablated platinum vapor with a mixture of a few percent of methane in argon. The newly determined permanent electric dipole moments obtained are 1.94(2)D (AЉ 1 ⌺ ϩ ) and 1.919(9)D (AЈ 1 ⌸). These results are discussed in terms of a proposed molecular orbital correlation diagram for platinum containing diatomics. The laser-induced fluorescence spectrum of the (0,0)AЉ 1 ⌺ ϩ -X 1 ⌺ ϩ transition of PtC has been re-recorded at high resolution ͑full width of half-maximum ϳ40 MHz͒ and analyzed to yield rotational constants for the four most abundant isotopomers of PtC, extending the previous analysis ͓Appelblad, Nilsson, and Scullman, Phys. Scr. 7, 65 ͑1973͔͒. The anomalously large value ͑ϳ15 MHz͒ for the newly derived nuclear-spin rotation parameter, C I ( 195 Pt), for the AЉ 1 ⌺ ϩ state is discussed.

Calculated structures of [Au=C=Au]2+ and related systems

“…The previous calculations on AuC þ and PtC showed, that both have a singlet ground state [1,7]. These results agree with experimental data for PtC [23,24].…”

“…d Experimental data taken from [23]. e Experimental data taken from [24]. The orbitals in brackets (2p g , 1d g and 1d u ) have no contribution from the carbon and are therefore not given.…”

Optical spectroscopy of jet-cooled NiSi

“…Rotationally resolved spectra recorded in this study have shown NiSi to have ⍀Љϭ0 in its ground state, which is consistent with the 1 ⌺ ϩ ground state predicted by theory. With the electronic ground states of the isovalent molecules NiC, 19,20 PdC, 21 PtC, 22,23 and PtSi ͑Refs. 13, 14͒ known to be 1 ⌺ ϩ as well, there is no reason to expect a different ground state for NiSi.…”

“…Several theoretical investigations of NiSi have been reported. 16 -18 All of these predict that the molecule has a 1 ⌺ ϩ ground state, as has been found in the isovalent NiC, 19,20 PdC, 21 PtC, 22,23 and PtSi ͑Refs. 13, 14͒ molecules.…”

Optical spectroscopy of tungsten carbide (WC)

“…16,[19][20][21][22] Since the invention of the laser ablation source, many more transition-metal monocarbides have been interrogated. 5,6,8,9,[23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] The 4d transition-metal monocarbides have been rather thoroughly investigated, 6,8,9,[27][28][29][30][31][32] with TcC, AgC, and CdC being the only members of this class that remain spectroscopically unexamined. Recent articles from this group examine the trends in the chemical bonding and electronic structure as the 4d series of transition-metal monocarbides is traversed.…”