Timeresolved infrared diode laser spectroscopy of the n

Previous Works on Co. NO production Matrix isolation + Ablation Ne + NO Abs.

MMW spectroscopy of Co. NO (cm-1) 2000 n 1 band 1000 2 n 2

Experiment NO 193 nm Ar. F Co OC CO CO photolysis Co(CO)3 NO 1774

Observed Spectrum n 1 fundamental P (58) P (42) P (26) P (55) 1775.

n 1　band n 1 fundamental n 1 + n 2 - n 2 Observed

Observed Spectrum n 1　band n 1 fundamental　 n 1 + n 2 – n

Observed infrared bands (cm-1) n 1+2 n 2(D, S) n 1 + n 3

Molecular Constants n 1 fundamental constant unit n 0 1796. 22371 (49) cm-1 B

NO and CO stretch frequency and Force constant shift CO cm-1 Freq. Force Constant

Electronic Configuration 　 p* 2 p* s* 4 s p back donation d s

NO frequencies shift of Metal-NO in Ne-Matrix NO　1875 cm-1 1900 (cm-1) 1500 (M-NO) Sc

Rotational Constants shift B (MHz) 2 n 2 (D) ● 4690 n 2 ●

Band origin value n 1 fundamental n 0 1796. 223 n 1 + n

Conclusions • High resolution infrared spectroscopy on Co. NO were performed, and　n 1 fundamental,

Energy diagram cm-1 w 2 DE’ n 1 +n 3 - n 3 DE’=63.

Rotational constant shift B Bn 1+2 n 2 (S) (6. 2 MHz) w B

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Time-resolved infrared diode laser spectroscopy of the n 1 band of Co. NO Takeo Soejima, Motoki Nakashima, Seiki Ikeda, and Keiichi Tanaka Department of Chemistry, Faculty of Science, Kyushu University, Japan (Columbus, Ohio, June 25 2005, FD 04 )

Previous Works on Co. NO production Matrix isolation + Ablation Ne + NO Abs. Cs. I NO Ne Co 1900 1800 cm-1 Ne-Matrix Co Co Yag laser (1064 nm) M. Zhou and L. Andrews, J. Phys. Chem. (2000). -1 (Ne-Matrix) n (N-O str. ) : 1794. 2 cm 　 1 n 2 (bend. ) : 302. 9 (calc. ) n 3 (Co-N str. ) : 620. 1 (Ar-Matrix)　　

MMW spectroscopy of Co. NO (cm-1) 2000 n 1 band 1000 2 n 2 G. S. n 3 Rotational spectrum of G. S. No splitting due to electron spin and orbital Co. NO linear →　1 S n 1 state is not observed High resolution infrared spectroscopy (RF 12) OSU symposium (2004).

Experiment NO 193 nm Ar. F Co OC CO CO photolysis Co(CO)3 NO 1774 ~ 1799 cm-1 diode laser Co. NO Co. CO 193 nm Co. NO P. D Ar Ar Pump A/D MCT detector Amp. Computer

Observed Spectrum n 1 fundamental P (58) P (42) P (26) P (55) 1775. 0 P (54) P (53) P (52) 1777. 0 1776. 0 P (37) P (36) 1782. 0 P (25) P (24) 1783. 0 P (51) P (50) P (22) P (21) 1778. 0 P (31) P (30) 1784. 0 P (20) P (49) P (48) P (47) P (29) 1786. 0 1785. 0 R (4) P (5) 1779. 0 P (28) P (27) 1787. 0 R (6) n 0 1788. 0 1789. 0 1794. 5 1798. 0 (cm-1)

n 1　band n 1 fundamental n 1 + n 2 - n 2 Observed Spectrum P (30) n 1 + n 3 - n 3 l-type doubling linear P (28) P (11) P (5) P (31) P (49) P (29) P (12) n 1 + 2 n 2 - 2 n 2 (S) n 1 + 2 n 2 - 2 n 2 (D) P (50) P (51) P (4) P(30) P (29)

Observed Spectrum n 1　band n 1 fundamental　 n 1 + n 2 – n 2　 n 1 + 2 n 2 - 2 n 2 (S) n 1 + 2 n 2 - 2 n 2 (D) P(29) P(28) P(27) P(4) P(5) R(15) R (23) 1786. 5 P(3) R(17) R(16) R (24) R (25) 1787. 0 R (26) cm-1

Observed infrared bands (cm-1) n 1+2 n 2(D, S) n 1 + n 3 n 1 + n 2 2000 n 1 1000 n 2 Ground State 2 n 2(D, S) n 3

Molecular Constants n 1 fundamental constant unit n 0 1796. 22371 (49) cm-1 B 1 4638. 432 (25) MHz D 1 1. 1299 (80) k. Hz B 0 4669. 7578 (29) MHz D 0 1. 1084 (13) k. Hz Co o 1. 583 A N ・ Ne-Matrix a 1 = 31. 325 (28) MHz a 2 -13. 0563 (79) MMW a 3 19. 609 (42) Be = 4676. 949 (51) MHz O 1. 182 (DFT) Bond strength 1794. 2 cm-1 o < r. C-O 0. 1 A shorter Co – C – O o 1. 688 A Co – N 　>　Co – C

NO and CO stretch frequency and Force constant shift CO cm-1 Freq. Force Constant NO 1875 cm-1 (1549 N/m) Co. CO 1796 Co. NO 2163 cm-1 (1891 N/m) 1974 (1143) ~ Dn =190 cm-1 40 % decrease (1252) ~ Dn =80 cm-1 20 % decrease red shift < 2 times larger Electronic configuration

Electronic Configuration 　 p* 2 p* s* 4 s p back donation d s 3 d p 5 s s Co Co. NO 2 D 1 S Co. CO NO CO

NO frequencies shift of Metal-NO in Ne-Matrix NO　1875 cm-1 1900 (cm-1) 1500 (M-NO) Sc Ti V Cr Mn Fe Co Ni Cu 1 A’ 2 A’ 1 A’ 2 A’’ 3 A’’ 2 D 1 S 2 A’ 1 A’ (state) linear Lester Andrews and Angelo Cita, Chem. Rev. (2002)

Rotational Constants shift B (MHz) 2 n 2 (D) ● 4690 n 2 ● G. S. 4670 8. 3 MHz 2 n 2 (S) n 1+2 n 2 (D) ● ● n 1+n 2 4650 ● ● ● 6. 2 MHz n 1+2 n 2 (S) n 1 ● 0 2 n 2 1 n 3 (S) D S Fermi interaction 2 (v 2)

Band origin value n 1 fundamental n 0 1796. 223 n 1 + n 2 - n 2　　 1787. 969 n 1 +2 n 2 - 2 n 2 S 1781. 79 D 1779. 523 n 1+n 3 - n 3 Unit 1788. 80 cm-1 X 12 : anharmonic term of vibration 2 X 12 (16. 7 cm-1) 2 n 2 (S) X 12 (8. 3 cm-1) n 2 hotband 2 n 2 (D) 2 n 2 (S) n 1 fundamental closely located states Fermi Interaction n 3 (S) 2. 3 cm-1 1780 1790 n 3 (S) (cm-1) 1800

Conclusions • High resolution infrared spectroscopy on Co. NO were performed, and　n 1 fundamental, n 1 + n 2 - n 2 , n 1 + n 3 - n 3, and n 1 + 2 n 2 - 2 n 2 were assigned. ・　The equilibrium structure was determined as follows. a 1 MHz 31. 325 (28) Be 4676. 949 (51) MHz Co o 1. 583 A • N O o 1. 182 A (Fix) The decrease of frequencies of NO stretch was explained by p back donation.

Energy diagram cm-1 w 2 DE’ n 1 +n 3 - n 3 DE’=63. 34 cm-1 n 1 +2 n 2 - 2 n 2 1788. 8 D S DE’+2 ( D w 2 DE’ S 1779. 5 w 2 DE n 3 1781. 79 DE=41. 83 cm-1 2 n 2 D D S w 2 DE DE+2 ( w 2 DE + 1779. 523 cm-1 = DE+2 ( w 2 DE’ S + 1781. 79 cm-1 w ) ) +1788. 80 cm-1 - 1781. 79 cm-1 = DE’+2 ( DE’ 2 w 2 DE ) )

Rotational constant shift B Bn 1+2 n 2 (S) (6. 2 MHz) w B 0 n 1+2 n 2 (S) - ( )2 DB DE’ DB (40 MHz) w B 0 n 1+n 3 + ( DE’ )2 DB Bn 1+n 3 (6. 2 MHz) DE’= 63. 34 cm-1