H-2-Me-D-Ser-OMe HCl

Dissociative recombination of electrons with HCl+, H2Cl+, DCl+, and D2Cl+ has been measured under thermal conditions at 300, 400, and 500 K using a flowing afterglow-Langmuir probe apparatus. Measurements for HCl+ and DCl+ employed the variable electron and neutral density attachment mass spectrometry (VENDAMS) method, while those for H2Cl+ and D2Cl+ employed both VENDAMS and the more traditional technique of monitoring electron density as a function of reaction time. At 300 K, HCl+ and H2Cl+ recombine with kDR = 7.7±2.14.5 × 10-8 cm3 s-1 and 2.6 ± 0.8 × 10-7 cm3 s-1, respectively, whereas D2Cl+ is roughly half as fast as H2Cl+ with kDR = 1.1 ± 0.3 × 10-7 cm3 s-1 (2σ confidence intervals). DCl+ recombines with a rate coefficient below the approximate detection limit of the method (≲5 × 10-8 cm3 s-1) at all temperatures. Relatively slow dissociative recombination rates have been speculated to be responsible for the large HCl+ and H2Cl+ abundances in interstellar clouds compared to current astrochemical models, but our results imply that the discrepancy must originate elsewhere.

We report the discovery of a potentially useful superconcentrated HCl at ambient temperature and pressure by using a simple surfactant-based reversed micelle system. Surprisingly, the molar ratios of H(+) to H(2)O (denoted as n(H+)/n(H2O)) in superconcentrated HCl can be larger than 5, while the maximum achievable n(H+)/n(H2O) value for conventional saturated HCl aqueous solution (37 wt %) is only about 0.28. Furthermore, both NMR and FT-IR results indicate that a significant amount of HCl remains in the molecular form rather than being ionized into H(+) and Cl(-). The superconcentrated HCl may promote some organic reactions that are not feasible by using conventional 37 wt % HCl solution. For example, addition reaction between C═C and HCl occurs in superconcentrated HCl solution without using catalysts.