Edwin F. Pearson

Millimeter‐Wave Spectrum and Structure of Hypofluorous Acid: HOF and DOF

The microwave spectra of two isotopic species of hypofluorous acid, HOF and DOF, have been investigated. The values of the A0, B0, and C0 rotational constants are 590 000, 26 758.00, and 25 512.51 MHz for HOF and 316 800, 25 591.25, and 23 587.75 MHz for DOF. The structural parameters calculated with these rotational constants are: r(O–H) = 0.964 ± 0.01 A, r(O–F) = 1.442 ± 0.001 A, and > HOF = 97.2° ± 0.6° Centrifugal distortion analysis in the symmetric top approximation gave DJ and DJK values of 0.0934 and 2.417 MHz for HOF and 0.0775 and 1.745 MHz for DOF, respectively. The P6 distortion term was not significant.

Rotational spectrum and structure of thioborine: HBS

The millimeter‐wave spectra of eight isotopic species of thioborine have been observed. This unstable molecule displays the rotational spectrum of a linear rotor. For the most abundant isotopic species, H11B32S, the rotational and centrifugal distortion constants are B0=19,083.006 MHz and D0=21.89 kHz. Complete substitution structures have been evaluated eight different ways from the variety of isotopic species observed. The resulting mean values for the B‐H and S‐B distances (in angstrom units) are 1.1692 and 1.5994, respectively.

Millimeter and Submillimeter Wave Spectrum and Molecular Constants of Aluminum Monofluoride

Rotational transitions of 27Al19F have been measured in the millimeter and submillimeter wave regions to frequencies of 461 Gc/sec. Vibrational states up to υ = 4 were observed. From analysis of the data the following Dunham rotational constants were obtained: Y01 = 16 562.930 ± 0.006 Mc/sec, Y11 = − 149.420 ± 0.009 Mc/sec, Y21 = 0.515 ± 0.004 Mc/sec, Y31 = 1.4 ± 0.6 kc/sec, Y02 = − 31.37 ± 0.02 kc/sec, and Y12 = 0.046 ± 0.014 kc/sec. The Dunham potential constants found are: a0 = 2.9167 ± 0.0019 × 105, a1 = − 3.1850 ± 0.0009, a2 = 6.82 ± 0.06, and a3 = − 11.6 ± 0.6 cm−1. The nuclear quadrupole coupling constants obtained are: eqQ(27Al) = − 37.59 ± 0.25 Mc/sec for υ = 0 and eqQ(27Al) = − 37.14 ± 0.6 Mc/sec for the υ = 1 vibrational state. Vibrational constants derived are ωe = 802.85 ± 0.25 cm−1 and ωexe = 4.86 ± 0.06 cm−1. The equilibrium internuclear distance re = 1.65436 ± 0.00002 A was obtained.

Centrifugal Distortion Analysis of Hypofluorous Acid: HOF and DOF

The millimeter wave rotational spectrum of hypofluorous acid displays sizeable distortion effects. More than forty lines each for both HOF and DOF including a‐ and b‐type transitions have been measured. A semirigid rotor Hamiltonian, which includes the quartic distortion terms, was employed to fit the spectrum. The special constants (in MHz) in the notation of Watson are for HOF: A= 585 631.20, B= 26 760.31, C= 25 510.19, ΔJ= 0.09414, ΔJK= 2.4146, ΔK= 82.52, δJ= 0.00432 and δK= 1.120. For DOF: A= 316 096.02, B= 25 593.91, C= 23 585.28, ΔJ= 0.07903, ΔJK= 1.7349, ΔK= 24.82, δJ= 0.005933 and δK= 1.183. Corrections to A, B, and C given above have been applied to obtain the effective moments of inertia, and the structure is recalculated.