1. Rotational transitions in the and vibrational states of cis-HCOOH 7 9 Oleg I. Baskakov Department of Quantum Radiophysics, Kharkov National University Kharkov, Ukraine Brenda P. Winnewisser, Ivan R. Medvedev, Frank C. De Lucia Department of Physics, The Ohio State University, Columbus, OH trans cis

2. trans-HCOOH [E/(hc)] /cm 0 500 1000 1500 2000 2500 GS trans GS cis 9 7 8 6 5 4 3 9 + 7 2 9 2 7 A' A'' A' A'' 7 9 cis-HCOOH

3. FASSST spectrum of HCOOH ― Frequency range: 115-186, 193-370 GHz ― Pathlength: 6 m ― Pressure: 1-10 mtorr (1.3-13.3 mbar) ― Temperature: 170 o C / 443 K ― Scan time/30 GHz: ~1.5 s ― Number of scans: ~200 up, ~200 down ― Calibration: SO 2 reference lines ― ~36 m ring-cavity interference fringes every 9.2 MHz ― Software correction for H 2 O in the atmosphere ― Estimated accuracy of line positions: 50 kHz [I. Medvedev et al., J. Mol. Spectrosc. 228, 314-328 (2004)]

4. The intensity of rotational transitions of the cis-rotamer gets a boost from its dipole moment. a-type transitions: factor of 3.5 b-type transitions: factor of 108

5. FASSST Spectrum of HCOOH GS, cis V = 1, cis 7 9 K =6 54 3 K = 6 5 4 3 a a a J = 7 – 6, a-type

6. Rotational and quartic centrifugal distortion constants of cis-HCOOH a ParameterGS b GSGS9191 7171 A86461.6235(22)86461.6124(12)84790.1785(19)87775.3411(30) B11689.18453(44)11689.18149(16)11648.04229(22)11695.76928(47) C10283.99637(50)10283.99126(15)10285.57554(21)10263.26555(47) JJ 0.00835515(97)0.00834931(18)0.00829231(37)0.0084343(14)  JK -0.0714412(43)-0.0714384(28)-0.0744141(62)-0.066785(14) KK 2.361672(46)2.361349(27)1.75816(13)2.95632(25) JJ 0.00141773(10)0.001419537(34)0.001376327(69)0.00145808(18) KK 0.040747(47)0.0411210(53)0.011002(14)0.068058(34) Number of trans. 620 (546 c ) 427336 J max 47 e (63 f ) 695245 K a max 12 e (16 f ) 16 SD / kHz 41 (37 d ) 3742 a Figures in parentheses represent one standard deviation in units of the last digit. b M. Winnewisser et al., J. Mol. Spectroscopy. 216, (2002) 259-265. C Number of the millimeter wave transitions measured in the present study. d Standard deviation of the millimeter wave transitions. e J max and K a max of the MMW and SMMW transitions. f J max and K a max of the FIR transitions.

7. Estimated parameters of the 9 and 7 states from the transitions with J  11 and Ka  5 using a model of interacting states Parameter9191 7171 A/MHz86030.(20.)86535.(20.) B/MHz11651.38(57)11693.47(54) C/MHz10284.965(21)10262.756(16)  J /MHz 0.00834931 a  JK /MHz -0.0714384 a  K /MHz 2.361349 a  J /MHz 0.001419537 a  K /MHz 0.0411210 a 7 - 9 cm -1 118.97(57)  a 7,9 0.382  b 7,9 0.133 a Quartic centrifugal distortion parameters are fixed to the respective ground state values.

8. O=CCHOCOHO=CHOCOHOC Ref. 21.1945(31)1.1050(43)1.3520(28)0.9555(53)123.23(58)122.12(37)109.68(44) Fitted1.189(10)1.1048(53)1.3595(98)0.9621(50)125.4(29)122.188(80)109.26(31) Refinement of structural parameters, calculated with the FC matrix from harmonic wavenumbers 1, centrifugal distortion constants 2, Coriolis coupling constants and ground state rotational constants 2. 1 M.Petterson, J.Lundell, L.Khriachtsev, M.Rasanen. J. Am. Chem. Soc. 119, (1997) 11715-11716. E.M.S.Macaos, J.Lundell, M.Petterson, L.Khriachtsev, R.Fausto, M.Rasanen, J. Mol. Spectroscopy. 219, (2003) 70-80. 2 E.Bjarnov, W.H.Hocking, Z.Naturforsch. 33a, (1978) 610-618. Bond lengths are in angstroms, angles are in degrees. Quoted figures in brackets give one standard deviation in the last significant digit.

9. cis a b

10. Parameters of the ground state of cis-H 13 COOH Parameter A 84201.7497(64) a B11687.51699(70) C10249.65459(62) JJ 0.0082881(11)  JK -0.069692(16) KK 0.230794(44) JJ 0.00144676(50) KK 0.040355(22)  JK  10 6 -9.29(45)  J  10 6 0.00397(45)  JK  10 6 -0.73(11) Number of transitions100 b Jmax29 Ka max8 SD / kHz54 c a Figures in brackets represent one standard deviation in the last digit. b Number of millimeter wave transitions measured in the present study. c Standard deviation of the millimeter wave transitions.

11. Funding provided by NASA ARO