Interstellar glycolaldehyde (CH OHCHO) has been detected in emission toward the Galactic center source 2

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The microwave spectra of nine isotopic species of borane monoammoniate (11BH3NH3, 10BH3NH3, 11BH3ND3, 10BH3ND3, 11BD3NH3, 11BH3 15NH3, 10BH3 15NH3, 11BD2HNH3, 11BH3ND2H) have been observed. The rotational constants, centrifugal distortion constants, dipole moment, torsional barrier, and molecular geometry of borane monoammoniate were determined from these spectra. The rs structure is: BN=1.6576(16) Å, BH=1.2160(17) Å, NH=1.0140(20) Å, ∠NBH=104.69(11), ∠BNH=110.28(14). The dipole moment is 5.216(17) D. The torsional barrier about the B–N bond, V3, is 2.047(9) kcal mol−1 for 11BH3ND2H and 2.008(4) kcal mol−1 for 11BD2HNH3.

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Interstellar glycolaldehyde (CH20HCHO) has been detected with the 100-m Green Bank Telescope (GBT) toward the star-forming region Sagittarius B2(N) by means of the 1~0 -1 0 1 , 2~1 -2~2 , 3~~-3 0~, and 413-404 rotational transitions at 13.48, 15.18, 17.98, and 22.14 GHz, respectively. An analysis of these four high signalto-noise rotational transitions yields a glycolaldehyde state temperature of ~8 K. Previously reported emission line detections of glycolaldehyde with the NRAO 12-m telescope at mm-wavelengths (71 GHz to 103 GHz) are characterized by a state temperature of -50 K. By comparison the GBT detections are surprisingly strong and seen in emission at 13.48 GHz, emission and absorption at 15.18 GHz, and absorption at 17.98 GHz and 22.14 GHz. We attribute the strong absorption observed by the GBT at the higher frequencies to the correspondingly smaller GBT beams coupling better to the continuum source(s) in Sagittarius B2(N). A possible model for the two-temperature regions of glycolaldehyde is discussed. Subject headings: ISM: abundances -ISM: clouds -ISM: individual (Sagittarius B2(N-LMH)) -ISM: moleculesradio lines: ISM