ACTA PHYSICA SINICA nm NO + ( X 1 + ) + N ( 4 S) = 8, 9) + N( 4 S) NO + ( X 1 +, v = 0, 1) + N ( 2 D), [7,8 ]

Transcript

1 Π2004Π53 (06) Π ACTA PHYSICA SINICA Vol 53 No 6 June 2004 ν 2004 Chin Phys Soc N 2 O + A g ( ) ( ; ) nm N 2 O (3 + 1) (REMPI) X 2 (000) N 2 O nm N 2 O + A 2 + TOF N 2 O + TOF E T ; E T 32000cm cm - 1 E T 8000cm cm cm - 1 ( X 1 + ) + N( 4 S) ; 32000cm - 1 ( X 1 + ) + N( 2 D) N ( 4 S) N 2 O + A 2 + : N 2 O + A 2 + TOF PACC: 3380G 8250G 3320L 11 [1 2 ] A 2 + O + ( 4 S) + N 2 ( X 1 + ) ( X 1 + v) + N( 4 S) ( X 1 + v ev (1) [1 ] [2 ] N 2 O + ( A 2 + ) N 2 O + 16 ] A 2 + A 2 + N 2 O + ( X 1 + ) + N( 4 S) 16 ] [3 6 ] N 2 O + A 2 + [ (000) 1 ( X 1 + ) + N ( 4 S) A [7 8 ] A 2 + (000) (100) [9 11 ] A 2 + A 2 + (000) A 2 + [15 ] (300) A 2 + ( X 1 + v) + N ( 4 [12 S) 16 ] Larzilliere [12 13 ] (100) (001) (200) v = 4 51 (300) Viard [14 ] = 8 9) + N( 4 S) ( X 1 + v = 0 1) + N ( 2 D) [8 14 A 2 + A (FIBLAS) (100) ( X 1 + ) + N ( 4 S) Viard [14 ] 2 (PEPICO) 3 ( G ) ( ) g E2mail edu cn ; : Tsinghua Tongfang Optical Disc Co Ltd All rights reserved

2 N 2 O ( 3 + 1) AΠD ( SR245 Stanford Research (REMPI) System) N 2 O + 10ns A cm - 1 Ne ( X 1 + ) + N( 2 D) N 2 O + A cm A 2 + (TOF) (MCP) MCP A 2 + Boxcar ( SR250 Stanford Research System) ( TOF) MCP [ ] (400MHz TDS380 Teltronix) Pa 1Π10 N 2 OΠHe N 2 O + ( PHOFEX) Boxcar Ne mm (general valve) 200 s 3111 PHOFEX 2 5cm 70LΠs 15LΠs (2X270 2X215 ) 28217nm 1500LΠs ( F2400 ( 35370cm - 1 ) ) ( ) N Pa Pa ( ) Pa 2 N 2 O Pa nm Nd : YAG(PRO2190 Spectra Physics) ( cm - 1 ) N 2 O + (532nm 470mJΠ (PHOFEX) 1 pulse) ( PRSC2LG218 Sirah) KD 3 P 30cm 2 N 2 O A 2 + v 1 v 2 Fermi (3 + 1) REMPI N 2 O nm 3mJ 1 PHOFEX N 2 O + A 2 + ( P [ i ]) X 2 1Π2 3Π2 (000) N 2 O + X 2 1Π2 3Π2 (000) [19 ] ( PRSC2L G224 A Sirah) KD 3 P P P = 2V 1 + V 2 60cm + 4V 3 i [20 ] A mJ PHOFEX Tsinghua Tongfang Optical Disc Co Ltd All rights reserved

3 6 :N 2 O + A N 2 O + 44ns TOF NO N 2 O + TOF cm cm - 1 PHOFEX P [ i ] A 2 + X 2 (000) A 2 + P N 2 O + ( t) 2 - ( t A 2 + X 2 X 2 0 ) 2 TOF ( (000) A 2 + z ) P ( V ( ) z f ( V z ) ) [21 23 ] G ( V ) A 2 + [24 ] g ( V) z X 2 [ ] Franck2Condon f ( V z 5417 ) = A G( V z - ) - g ( V) dv d 2V 1 (2) A 2 + f ( V z ) TOF h ( t - t 0 ) 3121 ( TOF) ( 32314nm) P( F T ) = g ( V) 135ns V nm ( TOF) TOF t t 0 ( N 2 O + TOF ) h ( t - t 0 ) = qe m f ( V z) (3) PHOFEX m q E TOF TOF N 2 O + 2 P( E T ) : Tsinghua Tongfang Optical Disc Co Ltd All rights reserved M N2 O + - m mm N2 O + (4)

4 P ( E T ) (2) (4) E T TOF E T nm TOF 2376cm - 1 TOF cm - 1 E T E T cm - 1 E T ( t) 2 - ( t 0 ) 2 ( X 1 + ) 2 3 E T ( t) cm ( t 0 ) 2 E T 32000cm - 1 E T E T 8000cm - 1 Larzilliere [13 ] A 2 + (100) ( 8800cm - 1 ) ( X 1 + ) nm TOF (5417 ) TOF ( ) ( ) E T 4 E T ( ) ( t) 2 - ( t 0 ) 2 ( ) t t 0 ( t) 2 - ( t 0 ) 2 E T ( t ) 2 - ( t 0 ) 2 E T + N( 4 S) ( A D 0A = cm - 1 ) ( X 1 + ) + N ( 2 D) ( B D 0B = 29660cm - 1 ) [25 ] 32000cm - 1 B 32000cm - 1 N 2 O + ( A 2 + ) A 32000cm ] B 32000cm ( h - D 0B ) P B C B (5) E T 8000cm - 1 C B B 1600cm cm - 1 E T P B 68 % C B 100 % Tsinghua Tongfang Optical Disc Co Ltd All rights reserved [12 N 2 O + ( A 2 + ) A B A B 32000cm - 1 E T 8000cm cm - 1 B A 20 % B A 32000cm - 1 B A A 32000cm - 1 E T E T E avl ( = h - D 0A ) P A 37 % A B P A P B 32000cm cm cm - 1 E T E T = ( h - D 0A ) P A (1 - C B )

5 6 :N 2 O + A cm - 1 A X 2 ( 000) A 2 + B B Franck2Condon cm N 2 O + A 2 + A 32000cm - 1 B 16 ] A 2 + ; [8 14 A Franck2Condon B ( X 1 + ) + N ( 4 S) A (29660 cm - 1 ) X 2 B ( X 1 + ) + N( 2 D) X 2 [15 ] X 2 Dehmer [22 ] Chen [23 ] A 2 + X cm - 1 A 2 + N + 2 N + 2 (35370cm - 1 ) B N 2 O + ( A 2 + ) X 2 A X cm - 1 B ( 32000cm - 1 ) N2 N 2 O + ( A 2 + ) N + 2 ( X 2 + g ) + O( 3 P 2 ) (35140cm - 1 ) [25 ] B X 2 A 2 + X 2 A 2 + X 2 N O + A 2 + B A ( X 1 + ) + N ( 4 S) ( X 1 + ) + N ( 2 D) B A N + 2 ( X 2 + g ) + O ( 3 P 2 ) 32000cm - 1 B A 32000cm - 1 A 1 PHOFEX 32000cm - 1 B ; N 2 O cm - 1 N X 2 A cm N 2 O + A Tsinghua Tongfang Optical Disc Co Ltd All rights reserved

6 N 2 O + A cm TOF ( X 1 + ) + N ( 4 S) B N + 2 E T 32000cm - 1 A 2 + X 2 2 E T 8000cm cm - 1 N + 2 N 2 O + A 2 + A A 2 + X 2 ( X 1 + ) + N ( 2 + D) N cm - 1 ( X 2 + g ) + O ( 3 P 2 ) A 2 + X cm - 1 A A 32000cm - 1 A X B B X cm - 1 [1] Burley J D Evin K M and Armentrout P B 1987 J Chem Phys [2] Komiha N 1994 J Mol Struct [3] Fellows C E and Vervloet M 2001 Chem Phys [4] Tsuji M and Maier J 1988 Chem Phys [5] Imamura T Imajo T and Koyano I 1995 J Phys Chem [6] Tokue I Kudo T and Ito Y 1992 Chem Phys Lett [7] Artes S M Barrio D Atabek O and Beswick J A 1983 Chem Phys Lett [8] Beswick J A and Horani M 1981 Chem Phys Lett 78 4 [9] Ibuki T and Sugita N 1984 J Chem Phys [10] Klapstein D and Maier J P 1981 Chem Phys Lett [11] Frey R Gotchev B Poatman W B Pollak H and Schlag E W 1978 Chem Phys Lett [12] Abed S Broyer M Carre M Gaillard M L and Larzilliere M 1983 Chem Phys [13] Lerme J Abed S Larzilliere M Holt R A and Carre M 1986 J Chem Phys [14] Viard M R Atabek O Dutuit O and Guyon P M 1990 J Chem Phys [15] Chambaud G Gritli H Rosmus P Werner H J and Knowles P J 2000 Mol Phys [16] Hopper D G 1978 J Am Chem Soc Hopper D G 1980 J Chem Phys [17] Zhang L M Chen J Xu H F Dai J H Liu S L and Ma X X 2001 J Chem Phys [18] Zhang L M et al 1999 Acta Phys Sin (in Chinese) [ ] [19] Scheper C R Kuijt J Buma WJ and delange C A 1998 J Chem Phys [20] Teffo J L Perevalov V I and Lyulin O M 1994 J Mol Spectrosc [21] Aarts J F M and Callomon J H 1982 Chem Phys Lett [22] Dehmer P M Dehmer J L and Chupka W A 1980 J Chem Phys [23] Chen W Liu J Ng C Y 2003 J Phys Chem A [24] Vasudev R Zare R N and Dixon R N 1984 J Chem Phys [25] Callomon J H and Creutzberg F 1974 Philis Trans Roy Soc Lond Ser A Tsinghua Tongfang Optical Disc Co Ltd All rights reserved

7 6 :N 2 O + A Photodissociation study of N 2 O + ( A 2 + ) ions 3 Xu Hai2Feng Li Qi2Feng Zhou Xiao2Guo Dai Jing2Hua Liu Shi2Lin g Ma Xing2Xiao ( Laboratory of Bond Selective Chemistry Department of Chemical Physics University of Science and Technology of China Hefei China) (Received 24 July 2003 ; revised manuscript received 13 October 2003) Pure parent ions N 2 O + Abstract populated at X 2 (000) were prepared by (3 + 1) multiphoton ionization of jet2cooled N 2 O molecules at nm and then were excited to different vibrational levels of predissociative A 2 + state by another laser in the wavelength range of nm The total released translational energies E T at different excitation energies were measured with a time2of2flight (TOF) spectrometer from the TOF broadenings of the fragment The E T value drops abruptly from 8000cm - 1 to 1600cm - 1 at excitation energy of 32000cm - 1 Further analysis shows that at the excitation energies below 32000cm - 1 the dissociation channel is ( X 1 + ) + N( 4 S) and at the energies above 32000cm - 1 a new channel ( X 1 + ) + N ( 2 D) is opened and replaces completely the N ( 4 S) channel The predissociation mechanism of the N 2 O + ( A 2 + ) ions was discussed based on the experimental results Keywords : N 2 O + ( A 2 + ) translational energy predissociation dynamics PACC: 3380G 8250G 3320L 3 Project supported by the State Key Development Program for Basic Research of China ( Grant No ) and the National Natural Science Foundation of China ( Grant No ) g edu cn ;Tel : Tsinghua Tongfang Optical Disc Co Ltd All rights reserved