Microwave, Submillimeter-Wave, and High-Resolution FTIR Study of SO(2)F(2) in the nu(8) State

The high-resolution infrared spectrum of the nu(8) band of SO(2)F(2) (nu(as) SF(2)) centered at 887.2 cm(-1) has been recorded with a resolution of 2.4 x 10(-3) cm(-1). More than 8000 transitions of the C-type band with DeltaK(a) = +/-1 (and in addition some DeltaK(a) = +/-3 transitions) have been assigned. Microwave and millimeter-wave spectra of the v(8) = 1 state up to 450 GHz have been recorded, and 177 pure rotational transitions have been measured. Rotational and rovibrational data have been combined, and excited state parameters up to sextic centrifugal distortion constants have been determined using a Watson-type Hamiltonian in S-reduction. No perturbation was indicated. Copyright 2000 Academic Press.

High-Resolution Study of the Mid-Infrared Region of FNO(2)

Of the gas-phase IR spectrum of nitrylfluoride, FNO(2), between 1200 and 1900 cm(-1), the bands nu(4), 2nu(6), nu(2) + nu(3), and nu(1) have been studied at a resolution of ca. 0.003 cm(-1). Improved ground state rotational and centrifugal distortion constants have been obtained from a simultaneous analysis of the data from F. Hegelund, H. Bürger, and G. Pawelke [J. Mol. Spectrosc. 184, 350-361 (1997)] and the present data from nu(4) and nu(1). The nu(4) and 2nu(6) bands are free from local perturbations, and upper state spectroscopic constants have been obtained from the conventional Watson Hamiltonian. The bands nu(1) and nu(2) + nu(3) are strongly perturbed by Coriolis interactions with the nearby dark levels nu(5) + nu(6), nu(3) + nu(6), and nu(2) + nu(5). Upper state constants for nu(1) and nu(2) + nu(3) are obtained from triad and tetrad models, respectively, including Coriolis resonances within this system. In addition Coriolis interaction parameters and the vibrational energies for the three dark states together with some of their rotational constants are determined from the observed perturbation effects on nu(1) and nu(2) + nu(3). Copyright 2000 Academic Press.

First High-Resolution Infrared Observation of the Symmetry-Forbidden nu(5) Band of (10)B(2)H(6)

Spectra of (10)B monoisotopic diborane, B(2)H(6), have been recorded at high resolution (2-3 x 10(-3) cm(-1)) by means of Fourier transform spectroscopy in the region 700-1300 cm(-1). A thorough analysis of the nu(18) a-type, nu(14) c-type, and nu(5) symmetry-forbidden band has been performed. Of particular interest are the results concerning the nu(5) symmetry-forbidden band, which is observed only because it borrows intensity through an a-type Coriolis interaction with the very strong nu(18) infrared band located approximately 350 cm(-1) higher in wavenumber. The nu(5) band has been observed around 833 cm(-1) and consists of a well-resolved Q branch accompanied by weaker P- and R-branch lines. Very anomalous line intensities are seen, with the low K(a) transitions being vanishingly weak, and Raman-like selection rules observed. The determination of the upper state Hamiltonian constants proved to be difficult since the corresponding energy levels of each of the bands are strongly perturbed by nearby dark states. To account for these strong localized resonances, it was necessary to introduce the relevant interacting terms in the Hamiltonian. As a result the upper state energy levels were calculated satisfactorily, and precise vibrational energies and rotational and coupling constants were determined. In particular the following band centers were derived: nu(0) (nu(5)) = 832.8496(70) cm(-1), nu(0) (nu(14)) = 977.57843(70) cm(-1), and nu(0) (nu(18)) = 1178.6346(40) cm(-1). (Type A standard uncertainties (1varsigma) are given in parentheses.) Copyright 2000 Academic Press.

First Observation of the nu(17)-nu(4) Difference Bands of Diborane (10)B(2)H(6) and (11)B(2)H(6)

An analysis of the nu(17)-nu(4) difference bands near 800 cm(-1) of two isotopic species, (10)B(2)H(6) and (11)B(2)H(6), of diborane has been carried out using infrared spectra recorded with a resolution of ca. 0.003 cm(-1). In addition, the nu(17) band of (10)B(2)H(6) has been recorded and assigned. Since this band in (11)B(2)H(6) had already been studied (R. L. Sams, T. A. Blake, S. W. Sharpe, J.-M. Flaud, and W. J. Lafferty, J. Mol. Spectrosc. 191, 331-342 (1998)), it was possible to derive precise energy levels and Hamiltonian constants for the 4(1) vibrational states of both isotopic species. Copyright 2000 Academic Press.

[Establishing a cytogenetic and morphological progression models of invasive breast cancer. Comparative genomic hybridization (CGH) in malignant and premalignant tumors of the female breast]

Ductal carcinoma in situ of the female breast and lobular carcinoma in situ are regarded as precursor lesions of invasive breast cancer. We used comparative genomic hybridization to analyze the genetic relationship between these two types of lesion and invasive breast cancer. The series included 166 patients with ductal or lobular carcinoma in situ and invasive breast cancer. Our results reflect the broad heterogeneity of morphologically different subtypes of invasive and noninvasive breast cancer. The data also provide evidence of multiple genetic pathways of invasive breast cancer associated with different morphological subtypes. In conclusion, we propose a combined model of morphological-genetic progression with various parallel pathways in the pathogenesis of invasive breast cancer.

Analysis of the (0 0 v(3)), v(3) = 1, 2, 3 Vibrotational States of HDSe

High-resolution Fourier transform spectra of HDSe in the region of the 2nu(3) and 3nu(3) bands were recorded and analyzed for five different (M)Se isotopic HDSe species. Energies obtained from rovibrational analyses of the (002) and (003) states, together with those taken of the (001) state from an earlier study [O. N. Ulenov, G. A. Onopenko, N. E. Tyabaeva, H. Bürger, and W. Jerzembeck, J. Mol. Spectrosc. 198, 27-39 (1999)], were used as input information for a "Global Fit" procedure. This fit provided 34 spectroscopic parameters for the HD(80)Se species which reproduced rotational-vibrational transitions of the (001), (002), and (003) states within experimental accuracy. Corresponding analyses were performed for the other (M)Se (M = 82, 78, 77, and 76) species. Copyright 2000 Academic Press.

Torsional Splitting in the Degenerate Vibrational States of (70)Ge(2)H(6): Rotation-Torsion Analysis of the nu(7) and nu(9) Fundamentals

The rotational and torsional structure of the nu(7) and nu(9) degenerate fundamentals of (70)Ge(2)H(6) has been analyzed under high resolution. The torsional structure of both v(7) = 1 and v(9) = 1 states can be fitted by a simple one-parameter formula. The x,y-Coriolis interaction with the parallel nu(5) fundamental was accounted for in the analysis of nu(7). A strong perturbation of the J structure of the E(3s) torsional component of the KDeltaK = -2 subbranches of nu(9) can be explained by the resonance with an E(3s) excited level of the pure torsional manifold. The perturber is centered at 361.58 cm(-1), very close to the value estimated with a barrier height of 285 cm(-1). This confirms that the fundamental torsional wavenumber is close to 103 cm(-1), in good agreement with the "ab initio" prediction. The torsional splittings of all the infrared active degenerate fundamentals, nu(7), nu(8), and nu(9), follow the trend predicted by theory, and have been fitted by exploratory calculations accounting only for the torsional Coriolis-coupling mechanism of all degenerate vibrational fundamentals in several torsional states. This confirms that torsional Coriolis coupling is the dominant mechanism responsible for the decrease of the torsional splitting in the degenerate vibrational states. A higher value of the barrier had to be used for the nu(9) mode. Copyright 2000 Academic Press.

High-Resolution Fourier Transform Spectra of HDSe: The Interacting States (v(1) v(2) v(3))/(v(1) +/- 1 v(2) -/+ 2 v(3)) with 2v(1) + v(2) = 1, 2, 3, and 4

For the first time, high-resolution Fourier transform spectra of HDSe in the region of the three polyads, nu(1)/2nu(2), nu(1) + nu(2)/3nu(2), and 2nu(1)/nu(1) + 2nu(2)/nu(2) + nu(3), have been recorded and analyzed. Combined with an earlier investigation of the nu(2) band, and including estimates for the unobserved "dark" 4nu(2) band, these levels were subjected to a "Global Fit," which makes use of relations between parameters within the different polyads. Since there are five isotopic species present in natural HD(M)Se (M = 82, 80, 78, 77, 76), altogether 34 vibration-rotation bands have been studied in the present contribution. The parameters determined by the Global Fit reproduce upper vibrational-rotational energies of all these bands with accuracies close to experimental precision. Copyright 2000 Academic Press.

High-Resolution Infrared Study of the nu(7), nu(8), and nu(15) Bands and Millimeter-Wave Investigation of the v(8) = 1 State of CF(2)Cl-CH(3)

High-resolution (Deltavarsigma = 2.3 and 2.9 x 10(-3) cm(-1)) FTIR spectra of natural and (35)Cl monoisotopic CH(3)CF(2)Cl have been recorded at -70 degrees C in the 600-1400 cm(-1) range. The bands nu(7), nu(8), and nu(15) have been rotationally analyzed for both isotopic varieties. With the help of predictions based on nu(8) parameters, the millimeter-wave spectrum of the (35)Cl species in the v(8) = 1 state has been observed and jointly fitted with the IR data. Only a small number of local perturbations have been detected in the spectra. Altogether more than 8000 IR transitions have been fitted with an experimental precision of ca. 3 x 10(-4) cm(-1). Copyright 2000 Academic Press.

High-Resolution Laser Photoacoustic Spectroscopy of HSiF(3): The 5nu(1) and 6nu(1) Overtone Bands

A spectrum of HSiF(3) has been recorded at room temperature with a gas pressure of 20-50 Torr in the near-infrared region. A laser photoacoustic spectrometer consisting of a longitudinal resonant cell coupled to a titanium:sapphire ring laser was employed. The 5nu(1) and 6nu(1) overtone bands of H(28)SiF(3) associated with the Si-H stretching have been observed at high resolution (3 x 10(-2) cm(-1)) in the regions 10 900-10 960 and 12 875-12 925 cm(-1), respectively. About 450 lines of the 5nu(1)-0 band have been assigned (J </= 45, K = 3p </= 18). Within each J cluster of the P and R branches, the K structure has been deconvoluted. A set of parameters characterizing the upper vibration-rotation structure has been obtained. Perturbations have been evidenced for K = 9 and 15. The characterization of the perturbed 6nu(1)-0 band was limited to J </= 38, and effective parameters have been determined with no detailed information on the K structure. Most perturbations are supposedly due to the cubic anharmonic constant &phi;(144) linking nnu(1) to (n - 1)nu(1) + 2nu(4) (n = 5, 6) and to their accompanying interacting rovibrational states. Copyright 2000 Academic Press.

Modulation of EGFR gene transcription by secondary structures, a polymorphic repetitive sequence and mutations--a link between genetics and epigenetics

The epidermal growth factor receptor (EGFR) plays a crucial role in growth, differentiation and motility of normal as well as tumor cells. The transduction of extracellular signals to the cytoplasm via the receptor not only depends on ligand binding, but is also determined by the receptor density on the cell surface. Therefore, in terms of cancer diagnosis and therapeutic approaches targeting EGFR it is decisive to know how the expression level of EGFR is controlled. We found that transcription activity declines with increasing numbers of CA dinucleotides of a highly polymorphic CA repeat in the first intron epidermal growth factor receptor gene. In vivo data from cultured cell lines support these findings, although other regulation mechanisms can compensate this effect. In addition, we showed that RNA elongation terminates at a site closely downstream of the simple sequence repeat (SSR) and that there are two separate major transcription start sites. Model calculations for the helical DNA conformation revealed a high bendability in the EGFR polymorphic region, especially if the CA stretch is extended. These data suggest that the CA-SSR can act like a joint bringing the promoter in proximity to a putative repressor protein bound downstream of the CA-SSR. The data suggest that this polymorphism is a marker for cancer linking genetic and epigenetic risk. Furthermore in breast cancer, heterozygous tumours with short CA-SSR showed an elevated EGFR-expression in contrast to tumours with longer CA-SSR. Tumours with loss of heterozygosity in intron 1 of egfr revealed an increased EGFR expression if the longer allele was lost. Moreover, deceased egfr gene dosages were significantly correlated to poor prognosis in breast cancer.

Increased angiogenesis in the bone marrow of patients with acute myeloid leukemia

The importance of angiogenesis for the progressive growth and viability of solid tumors is well established. In contrast, only few data are available for hematologic neoplasms. To investigate the role of angiogenesis in acute myeloid leukemia (AML), bone marrow biopsies from 62 adults with newly diagnosed, untreated AML (day 0) were evaluated. Further studies were done after the completion of remission induction chemotherapy (day 16 of induction chemotherapy, n = 21; complete remission, n = 20). Microvessels were scored in at least 3 areas (x500 field, 0.126 mm(2)) of the highest microvessel density in representative sections of each bone marrow specimen using immunohistochemistry for von Willebrand factor and thrombomodulin. Microvessel counts were significantly higher in patients with AML (n = 62) compared with control patients (n = 22): median (interquartile range) 24.0 (21.0-27.8)/x500 field vs 11.2 (10. 0-12.0)/x500 field, respectively (P <.001). On day 16 of induction chemotherapy, microvessel density was reduced by 60% (44-66) (P <. 001) in hypoplastic marrows without residual blasts, in contrast to only 17% (0-37) reduction in hypoplastic marrows with >/= 5% residual blasts (P <.001 for the difference between both groups). Bone marrow biopsies taken at the time of complete remission displayed a microvessel density in the same range as the controls. In conclusion, there is evidence of increased microvessel density in the bone marrow of patients with AML, which supports the hypothesis of an important role of angiogenesis in AML. Furthermore, these findings suggest that antiangiogenic therapy might constitute a novel strategy for the treatment of AML. (Blood. 2000;95:2637-2644)

High-Resolution Infrared and Millimeter-Wave Study of the v(3) = 1 State of HSiF(3) and DSiF(3)

Millimeter-wave spectra of HSiF(3) and DSiF(3) in the v(3) = 1 excited state have been measured from 100 to 490 GHz. Infrared spectra have been recorded in the nu(3) regions, nu(0) 424.0301 and 420.9320 cm(-1) in HSiF(3) and DSiF(3), respectively, with a resolution of 2.4 x 10(-3) cm(-1). Since in both species the parameters alpha(B)(3) and alpha(C)(3) have very similar values, no K structure could be resolved in the (Q)P and (Q)R clusters for low-to-medium K values. For high J the effect of the ground state D(JK) term more and more dominates and spreads the J clusters into opposite directions such that medium-to-high K components, particularly those with K = 3p, are resolved. Rotational and infrared data have been fitted together using a model up to sextic centrifugal distortion constants. No perturbations were indicated. Hot bands (nu(3) + nnu(6))-nnu(6) with n = 1, 2, and 3 have been detected and analyzed. Copyright 2000 Academic Press.

High-Resolution Spectrum and Rovibrational Analysis of the nu(2)/nu(5) Dyad of D(3)SiF near 700 cm(-1)

The nu(2) (A(1), 710.157 cm(-1)) and nu(5) (E, 701.717 cm(-1)) fundamental bands of D(3)(28)SiF have been studied by FTIR spectroscopy with a resolution of 2.4 x 10(-3) cm(-1). We assigned 1648 lines for the parallel band (J(max) = 50, K(max) = 21), 4279 for the perpendicular band (J(max) = 52, K(max) = 27), and in addition 671 perturbation-allowed transitions (J(max) = 50, K(max) = 12). The nearly degenerate v(2) = 1 and v(5) = 1 states are linked by (DeltaK = +/-1, Deltal = +/-1) and (DeltaK = +/-2, Deltal = -/+1) interactions, while the l(5) = +/-1 levels of nu(5) interact also by l(2, -1), l(2, 2), and l(2, -4) interactions. The first model with 36 free parameters, taking into account all these resonances through a nonlinear least-squares program, gave standard deviations of 1.56 x 10(-4) cm(-1) for 5997 nonzero-weighted IR data and 138 kHz for 8 MW data from the literature. The second model, in which the main Coriolis term was constrained to a force field value, used 37 parameters and gave similar standard deviations. A new determination of the A(0) and D(0)(K) ground state parameters was performed by two methods: either using differences between "forbidden" transitions differing by 3 in K or letting A(0) and D(0)(K) free in the global fit. The values obtained are fully compatible with those obtained previously by the "loop method." Copyright 2000 Academic Press.

Radiofrequency, Centimeter-Wave, Millimeter-Wave, and Infrared Spectra of SiHF(3): Investigation of the Ground, v(4) = 1, and v(6) = 1 Vibrational States

The present paper deals with the analysis of the microwave, millimeter-wave, and infrared spectra of (28)SiHF(3) in its ground, v(6) = 1 and v(4) = 1 excited states. The former was observed up to 1055 GHz leading to the determination of one octic centrifugal distortion constant, L(J) = -0.0749(55) µHz. Furthermore the <k ||H ||k +/- 6> interaction term ||h(3,GS) || = 1.1032(70) mHz has been fitted from splittings of six K = 3 lines. The excited states have been regarded as isolated ones. This enabled fits according the Q-, D-, and QD-reduction schemes proposed by E. I. Lobodenko, O. N. Sulakshina, V. I. Perevalov, and Vl. G. Tyuterev, (J. Mol. Spectrosc. 126, 159-170 (1987)) and further developed by J. K. G. Watson, C. Gerke, H. Harder, and K. Sarka, (J. Mol. Spectrosc. 187, 131-141 (1997)) and Harder (J. Mol. Spectrosc. 194, 145 (1999)). A multiple fit analysis was performed confirming the assumption that the excited states are not affected by intervibrational resonances. Finally the millimeter spectrum of (29)SiHF(3) and (30)SiHF(3) in their ground state was also measured up to 460 GHz and accurate rotational and centrifugal distortion parameters were derived. Copyright 2000 Academic Press.

Centrifugal Distortion Analysis of a Near-Spherical Top, SO(2)F(2): The First Determination of All Six Quartic Centrifugal Distortion Constants for an Asymmetric Top

The rotational spectrum of the near-spherical top molecule SO(2)F(2) (sulfuryl fluoride) has been investigated by microwave Fourier transform spectroscopy and by millimeter-wave spectroscopy. The ground state spectrum has been measured from 10 to 472 GHz. One of the reasons for studying this molecule is that it is a nearly spherical top and we wanted to verify our theoretical prediction that for such a molecule all six quartic centrifugal distortion constants (and nine sextic distortion constants) should be determinable, while for a standard asymmetric rotor, Watson has shown that only five quartic and seven sextic distortion constants are determinable. The analysis of the spectra confirmed our predictions, because all six quartic constants were well determinable. The results have been confirmed independently by ab initio calculations of the force field and quartic distortion constants. Because the molecule is relatively heavy, contributions of some sextic constants are too small and we have not been able to determine all nine sextic constants predicted by theory. Copyright 2000 Academic Press.

High-Resolution Infrared Spectrum of BrCN in the nu(2) and nu(1)/2nu(2) Regions

FT infrared spectra of BrCN have been recorded in the region of the nu(2) band near 340 cm(-1), the nu(1) band near 580 cm(-1), and the 2nu(2) band near 690 cm(-1) with a resolution between 2.9 and 4.7 x 10(-3) cm(-1). The vibrational levels (01(1)0), (10(0)0), (02(0)0), (02(2)0), (11(1)0), and (20(0)0) have been analyzed employing cold bands, hot bands, and new millimeter-wave transitions. Band-by-band polynomial analyses and a combined fit of all data relevant to the 2v(1) + v(2) = 2 polyad levels have been performed. The latter fit considered l-resonance interactions between the (02(0)0), e and (02(2)0), e levels and Fermi resonance between the two Sigma states (10(0)0) and (02(0)0). Altogether about 1000 pieces of data up to J = 100 were fitted for each of the two isotopic species with rms of the residuals of 2-8 x 10(-4) cm(-1) for the infrared and 10-120 kHz for the pure rotational data. Copyright 2000 Academic Press.

Rovibrational Spectroscopy of the v(5) = 1 Level of (28)SiDF(3)

The nu(5) fundamental band of trifluorosilane-d (SiDF(3)) at 627 cm(-1) was studied for the first time by high-resolution FTIR spectroscopy at a resolution of 2.4 x 10(-3) cm(-1). The analysis was performed simultaneously with available microwave and newly measured submillimeter-wave data in the approximation of an isolated degenerate fundamental level of a C(3 Kv) symmetric top molecule leading to a standard deviation of 0.22 x 10(-3) cm(-1) for the reproduction of the infrared wavenumbers, 36 kHz for the microwave, and 198 kHz for the submillimeter-wave frequencies, respectively. The unitary equivalence between the two reductions (Q and D) of the effective Hamiltonian applied in the analysis is demonstrated. Copyright 2000 Academic Press.

Analysis of Rotational and Rovibrational Spectra of SiDF(3) in the Ground and v(4) = 1 Excited States

This paper presents the analysis of the spectra of SiDF(3) in its vibrational ground and v(4) = 1 states. The pure rotational spectrum of the ground state was measured up to 903 GHz (J" = 65). Rotational, quartic, and sextic centrifugal distortion constants were accurately determined. Furthermore the parameter ||h(3) || = 7.64(11) x 10(-4) Hz was derived from the observation of A(1)-A(2) splittings of six K = 3 lines. The assignment of the v(4) = 1 spectrum was performed by combining 140 pure rotational frequencies and more than 2300 rovibrational transitions. Among them, because of the strong (+/-2, -/+4) interaction, there are more than 90 A(1)-A(2) resolved split transitions between the (l = 0, k = +/-3) ground state levels and the (l = +/-2, k = -/+1) v(4) = 1 levels. Although the v(4) band is located at about 994.3 cm(-1), the energies of the other fundamental bands are at a distance of more than 140 cm(-1). The assumption of the isolated character of the state was confirmed by the small differences between the v(4) = 1 state and the ground state parameters and by the possibility of using the D and Q reduction schemes proposed by E. I. Lobodenko, O. N. Sulakshina, V. I. Perevalov, and Vl. G. Tyuterev [J. Mol. Spectrosc. 126, 159-170 (1987)]. Copyright 1999 Academic Press.

Isotope Substitution in Near Local-Mode H(2)X Molecules: Stretching Fundamental Bands of HDSe

The high-resolution FTIR spectrum of the HDSe molecule in the presence of H(2)Se and D(2)Se was recorded on (80)Se monoisotopic and natural samples in the 1500-2900 cm(-1) region and theoretically analyzed in the regions of the stretching fundamental bands nu(1) and nu(3) near 1692 and 2351 cm(-1), respectively. The analysis was performed starting from derived isotopic relations between vibration-rotation, anharmonic, centrifugal distortion, and other parameters which reveal high predictive power. Strong resonance interactions between the states (100) and (020) are taken into account, and sets of parameters which reproduce the experimental rotation-vibration energies of the (100) and (001) states with a mean accuracy of 0.00008 and 0.00009 cm(-1), respectively, for the HD(80)Se species, were obtained. For the less abundant species, for which some higher order terms were constrained, slightly worse agreement was achieved. The refined spectroscopic parameters are very close to their predicted values. Copyright 1999 Academic Press.

The nu(2) Bands of the Deuterated Species D(2)Se and HDSe

For the first time D(2)Se and HDSe as (80)Se monoisotopic and natural material were studied in the region of the nu(2) fundamental vibration by high-resolution (0.0033 cm(-1)) Fourier transform infrared spectroscopy. For D(2)Se which is an asymmetric rotor with C(2v) symmetry the nu(2) band is of B type while for HDSe (C(s) symmetry) it is a hybrid band, and both A- and B-type transitions were observed. Depending on the isotopic abundances, 300-1000 lines were assigned for each of the isotopic (M)Se species (M = 76, 77, 78, 80, and 82). The corresponding (010) experimental rotational levels, obtained by adding the observed line positions to the ground state levels derived from J.-M. Flaud, Ph. Arcas, O. N. Ulenikov, G. A. Onopenko, N. E. Tyabaeva, W. Jerzembeck, and H. Bürger, (J. Mol. Spectrosc., in press) were fitted satisfactorily using a Watson-type Hamiltonian in A reduction and I(r)-representation: the rms deviations are ranging from 1.5 to 4.3 x 10(-4) cm(-1) depending on the isotopic species. Hamiltonian constants up to high order (octic terms) were determined for each isotopic species. For the most abundant Se isotopic species, namely (80)Se, the band centers are nu(0) (D(2)(80)Se) = 741.67503 cm(-1) and nu(0) (HD(80)Se) = 900.43820 cm(-1). Copyright 1999 Academic Press.

High-Resolution IR Spectrum of SCF(2) from 1000 to 1400 cm(-1): The nu(1)/nu(3) + 2nu(5)/nu(2) + nu(3) and nu(4)/nu(2) + nu(5) Interacting States

The infrared spectrum of SCF(2) was recorded in the 1000-1400 cm(-1) region with a resolution of 2.5 x 10(-3) cm(-1). The rotationally resolved nu(1) and nu(4) band systems were studied for the first time, and altogether 11 500 transitions were assigned. Both fundamentals are involved in strong anharmonic (Fermi) resonances. Effective centers (J = K(a) = K(c) = 0) of the interacting bands are nu(1) 1366.7117 cm(-1), nu(3) + 2nu(5) 1365.4257 cm(-1), nu(2) + nu(3) 1311.1491 cm(-1) (a(1) species), and nu(4) 1190.0839 cm(-1), nu(2) + nu(5) 1217.8191 cm(-1) (b(1) species). The strong K(a) dependence of the nu(1)/nu(3) + 2nu(5) level mixing enabled a numerical determination of the interaction constants while the other anharmonic interactions were accounted for by consideration of relative intensities. Deperturbed band centers, anharmonicity constants, and equilibrium and excited state rotational and centrifugal distortion constants were determined. Copyright 1999 Academic Press.