Quenching of excited P11 state atomic zinc by molecular nitrogen: A matrix-isolation spectroscopy/quantum chemical calculation study

Abstract

A concentration study is used to identify the optical absorption of zinc atoms isolated in solid nitrogen. Photoexcitation of the threefold-split, atomic 4p 1 P 1 singlet absorption band did not produce any emission from either the singlet or triplet states. Hartree-Fock ͑relativistic effective core potentials͒ plus variational and multireference perturbational configuration-interaction calculations are performed to analyze this very efficient quenching of excited state atomic zinc by molecular nitrogen. Of the two geometries considered in energy calculations of the approach of Zn( 1 P 1 ) to N 2 , the collinear exhibited a slightly greater stabilization than the perpendicular approach. However, the collinear is identified as of no significance in the excited state quenching due to the absence of low energy crossings with the ground state. In contrast, for the perpendicular approach a crossing between the repulsive ground 1 A 1 ( 1 S 0 ) state and the strongly attractive 1 B 2 ( 1 P 1 ) state occurs close to the energy minimum of the 1 B 2 state. The efficiency of crossing between these states is analyzed in the framework of one-dimensional Landau-Zener ͑LZ͒ theory. A hopping probability of 0.07 is obtained for a single crossing, considered important in a rapidly relaxing solid state system, such as present in a low temperature matrix. Crossings found between the repulsive 3 B 1 ( 3 P 1 ) and 3 A 1 ( 3 P 1 ) states with the strongly bound 1 B 2 ( 1 P 1 ) state are expected to play a role in gas phase Zn( 1 P 1 ) quenching leading to the production of Zn( 3 P J ) states. LZ calculations indicate a small hopping probability for these crossings, consistent with the small 1 P 1 → 3 P J quenching cross sections observed in the gas phase work.

Activity of Closed d-Shells in Noble Metal Atoms

“…This however must be referred to the original publications (Castillo et al, 1994;Colmenares et al, 2001).…”

“…More recently the laboratory of John MacCaffrey in Ireland invited us to do joint research (Colmenares et al, 2001) on the activation of N 2 by Zn at cryogenic conditions. We do not need to emphasize the crucial role that nitrogen activation has for modern agriculture.…”

“…We do not need to emphasize the crucial role that nitrogen activation has for modern agriculture. Both the C 2v and C ¥ approaches of N 2 to zinc were studied (Colmenares et al, 2001) the latter being the most favorable (lone pair bonding to Zn, etc.). Figure 11 shows the repulsion of the ground Zn state to N 2 while the triplet and singlet states stemming from the 3 P(3d 10 4s 1 4p 1 ) are attractive.…”

“…Figure 11 shows the repulsion of the ground Zn state to N 2 while the triplet and singlet states stemming from the 3 P(3d 10 4s 1 4p 1 ) are attractive. A series of surface hopping processes using the Landau-Zenner theory were studied in (Colmenares et al, 2001), including both C 2v and C ¥ symmetries, singlet crossings, singlet/triplet crossings, etc. A very Figure 11.…”

Metal atom (Zn, Cd and Mg) luminescence in solid neon

“…While much fewer matrix studies have been done on metal atoms in solid neon [4], absorption spectra of the three metals of interest to this work have been recorded. In stark contrast to the heavier rare gases, absorption spectra of the Mg/Ne [8], Cd/Ne [12] and Zn/Ne [13][14][15] systems do not show clear evidence of threefold splitting. Instead the Mg/Ne system exhibits a single featureless band, Zn/Ne shows evidence for a weak red-shoulder on a main band, while Cd/Ne presents a resolved red feature close to the main band which is featureless.…”