Site of protonation and conformational effects on gas-phase basicity in .beta.-amino alcohols. The nature of internal hydrogen bonding in .beta.-hydroxy ammonium ions

1983 ◽  
Vol 105 (11) ◽  
pp. 3417-3422 ◽  
Author(s):  
Raymond Houriet ◽  
Hermann Ruefenacht ◽  
Pierre Alain Carrupt ◽  
Pierre Vogel ◽  
Milos Tichy
Keyword(s):  
Hydrogen Bonding ◽  
Gas Phase ◽  
Amino Alcohols ◽  
Ammonium Ions ◽  
Internal Hydrogen ◽  
Conformational Effects

Raman Spectra of Solid (NH4)2CrO4 and (ND4)2CrO4 Obtained by a Rotating Cell Technique

1976 ◽  
Vol 30 (2) ◽  
pp. 187-190 ◽  
Author(s):  
Robert L. Carter ◽  
L. Kevin O'Hare
Keyword(s):  
Hydrogen Bonding ◽  
Alkali Metal ◽  
Raman Spectra ◽  
Sampling Technique ◽  
Solid Sampling ◽  
Monoclinic Structure ◽  
Ammonium Ions ◽  
Cylindrical Cell ◽  
Sample Rotation ◽  
Rotation Technique

The Raman spectra of polycrystalline (NH4)2CrO4 and (ND4)2CrO4 have been obtained by a sample rotation technique where the uncompressed solid is contained in a glass cylindrical cell. The apparatus is a commerically available sample rotator for liquids, which was modified for the described solid sampling technique. The Raman spectra of (NH4)2CrO4 and (ND4)2CrO4 are discussed in relation to their uniquely monoclinic structure, in contrast to the β-K2SO4 structure found for (NH4)2SO4 and many alkali metal chromates and sulfates. The hydrogen bonding in (NH4)2CrO4 is described, and its role in determining both the structure and the Raman spectra is discussed. The data suggest a barrier to NH4+ rotation of approximately 3.70 kcal/mol, indicating that the ammonium ions are not freely rotating on the time scale of the Raman experiment (10−13 sec).

scholarly journals Amines in boreal forest air at SMEAR II station in Finland

2018 ◽  
Vol 18 (9) ◽  
pp. 6367-6380 ◽  
Author(s):  
Marja Hemmilä ◽  
Heidi Hellén ◽  
Aki Virkkula ◽  
Ulla Makkonen ◽  
Arnaud P. Praplan ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Gas Phase ◽  
Particle Number ◽  
Detection Limits ◽  
Ambient Air ◽  
Monthly Means ◽  
Ammonium Ions ◽  
Quadrupole Mass ◽  
Concentration Data ◽  
Diurnal Variability

Abstract. We measured amines in boreal forest air in Finland both in gas and particle phases with 1 h time resolution using an online ion chromatograph (instrument for Measuring AeRosols and Gases in Ambient Air – MARGA) connected to an electrospray ionization quadrupole mass spectrometer (MS). The developed MARGA-MS method was able to separate and detect seven different amines: monomethylamine (MMA), dimethylamine (DMA), trimethylamine (TMA), ethylamine (EA), diethylamine (DEA), propylamine (PA), and butylamine (BA). The detection limits of the method for amines were low (0.2–3.1 ng m−3), the accuracy of IC-MS analysis was 11–37 %, and the precision 10–15 %. The proper measurements in the boreal forest covered about 8 weeks between March and December 2015. The amines were found to be an inhomogeneous group of compounds, showing different seasonal and diurnal variability. Total MMA (MMA(tot)) peaked together with the sum of ammonia and ammonium ions already in March. In March, monthly means for MMA were < 2.4 and 6.8 ± 9.1 ng m−3 in gas and aerosol phases, respectively, and for NH3 and NH4+ these were 52 ± 16 and 425 ± 371 ng m−3, respectively. Monthly medians in March for MMA(tot), NH3, and NH4+ were < 2.4, 19 and 90 ng m−3, respectively. DMA(tot) and TMA(tot) had summer maxima indicating biogenic sources. We observed diurnal variation for DMA(tot) but not for TMA(tot). The highest concentrations of these compounds were measured in July. Then, monthly means for DMA were < 3.1 and 8.4 ± 3.1 ng m−3 in gas and aerosol phases, respectively, and for TMA these were 0.4 ± 0.1 and 1.8 ± 0.5 ng m−3. Monthly medians in July for DMA were below the detection limit (DL) and 4.9 ng m−3 in gas and aerosol phases, respectively, and for TMA these were 0.4 and 1.4 ng m−3. When relative humidity of air was > 90 %, gas-phase DMA correlated well with 1.1–2 nm particle number concentration (R2=0.63) suggesting that it participates in atmospheric clustering. EA concentrations were low all the time. Its July means were < 0.36 and 0.4 ± 0.4 ng m−3 in gas and aerosol phases, respectively, but individual concentration data correlated well with monoterpene concentrations in July. Monthly means of PA and BA were below detection limits at all times.

Optimization of a phosphine oxide disulfoxide array for multipoint hydrogen bonding to ammonium ions

1993 ◽  
Vol 115 (17) ◽  
pp. 7900-7901 ◽  
Author(s):  
Paul B. Savage ◽  
Steven K. Holmgren ◽  
Samuel H. Gellman
Keyword(s):  
Hydrogen Bonding ◽  
Phosphine Oxide ◽  
Ammonium Ions
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