Improved source of NF(b sup 1. Sigma. sup + ) molecules: Spectroscopic constants and evidence for E-V energy-transfer reactions with CH sub 4 and H sub 2 O

Journal Article · Thu Nov 14 04:00:00 EST 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100176a058· OSTI ID:7163724

Du, K; Setser, D W ^[1]

---

1. Kansas State Univ., Manhattan (United States)

A low-power dc discharge in a dilute flow of NF{sub 2} in Ar carrier gas provides a source of NF(b) molecules in the concentration range (2-5) {times} 10{sup 11} molecules cm{sup {minus}3}, which is 20-50 times larger than the concentration from the reaction of Ar({sup 3}P{sub 0,2}) with NF{sub 2} for the same conditions in the flow reactor. The discharge source gives high vibration levels, v{prime} {le} 11, and the NF(b{sup 1}{Sigma}{sup +} {yields} X{sup 3}{Sigma}{sup {minus}}) spectrum had strong bands for the {Delta}v = {plus minus}2 sequences. The extended spectrum from high-v{prime} levels provides improved vibrational constants, {omega}{double prime}{sub e} = 1136.7 {plus minus} 3.3 and {omega}{double prime}{sub e}x{double prime}{sub e} = 8.9 {plus minus} 0.9 cm{sup {minus}1}; {omega}{prime}{sub e} = 1,191.1 {plus minus} 3.7 and {omega}{prime}{sub e}x{prime}{sub e} = 8.2 {plus minus} 1.o cm{sup {minus}1}. The dependence of the NF(b {yields} X) transition dipole upon the {bar r} centroid was assigned as {minus}5.4075 + 9.0695{bar r}-3.2183{bar r}{sup 2} for 1.0 {le} {bar r} {le} 1.8 {angstrom}. The direct observation of NF(a{sup 1}{Delta}) formation from the quenching of NF(b{sup 1}{Sigma}{sup +}) by CH{sub 4} and H{sub 2}O proved that E-V energy transfer is the major channel for NF(b) deactivation. The E-V quenching data are consistent with the accepted radiative lifetime of NF(a).

• OSTI ID: 7163724
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:23; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKANES
CHEMICAL PREPARATION
ELECTRIC DISCHARGES
ENERGY LEVELS
ENERGY TRANSFER
EXCITED STATES
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HYDROCARBONS
HYDROGEN COMPOUNDS
METHANE
NITROGEN COMPOUNDS
NITROGEN FLUORIDES
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
QUENCHING
SYNTHESIS
VIBRATIONAL STATES
WATER