GC-MS with photoionization of cold molecules in supersonic molecular beams-Approaching the softest ionization method.

A new type of photoionization ion source was developed for the ionization of cold molecules in supersonic molecular beams (named Cold PI). The system was based on a GC-MS with supersonic molecular beams and its fly-through EI of cold molecules ion source (Cold EI) plus quadrupole mass analyzer. A continuously operated deuterium VUV photoionization lamp was added and placed above and between the supersonic nozzle and skimmer whereas the Cold EI ion source served only as a portion of the ion transfer ion optics.

Liquid-State NMR Analysis of Nanocelluloses.

Recent developments in ionic liquid electrolytes for cellulose or biomass dissolution has also allowed for high-resolution H and C NMR on very high molecular weight cellulose. This permits the development of advanced liquid-state quantitative NMR methods for characterization of unsubstituted and low degree of substitution celluloses, for example, surface-modified nanocelluloses, which are insoluble in all molecular solvents. As such, we present the use of the tetrabutylphosphonium acetate ([P][OAc]):DMSO- d electrolyte in the 1D and 2D NMR characterization of poly(methyl methacrylate) (PMMA)-grafted cellulose nanocrystals (CNCs).

WtF-Nano: One-Pot Dewatering and Water-Free Topochemical Modification of Nanocellulose in Ionic Liquids or γ-Valerolactone.

Ionic liquids are used to dewater a suspension of birch Kraft pulp cellulose nanofibrils (CNF) and as a medium for water-free topochemical modification of the nanocellulose (a process denoted as "WtF-Nano"). Acetylation was applied as a model reaction to investigate the degree of modification and scope of effective ionic liquid structures. Little difference in reactivity was observed when water was removed, after introduction of an ionic liquid or molecular co-solvent.

Synthesis of Tertiary and Quaternary Amine Derivatives from Wood Resin as Chiral NMR Solvating Agents.

Chiral tertiary and quaternary amine solvating agents for NMR spectroscopy were synthesized from the wood resin derivative (+)-dehydroabietylamine (2). The resolution of enantiomers of model compounds [Mosher's acid (3) and its n-Bu₄N salt (4)] (guests) by (+)-dehydroabietyl-N,N-dimethylmethanamine (5) and its ten different ammonium salts (hosts) was studied. The best results with 3 were obtained using 5 while with 4 the best enantiomeric resolution was obtained using (+)-dehydroabietyl-N,N-dimethylmethanaminium bis(trifluoromethane-sulfonimide) (6).

Synthesis and applications of secondary amine derivatives of (+)-dehydroabietylamine in chiral molecular recognition.

(+)-Dehydroabietylamine (1a), the novel derivatives (2a-6a) and their NTf2 salts (1b-6b) were tested as chiral NMR solvating agents for the resolution of enantiomers of the model compound Mosher's acid (7) and its n-Bu4N salt (8). Best enantiomeric discrimination of 7 was obtained using bisdehydroabietylamino-N(1),N(2)-ethane-1,2-diamine (6a), and of 8 using N-(dehydroabietyl)-2-(dehydroabietylamino)ethanaminium bis((trifluoromethyl)-sulfonyl)-amide (6b). For the maximal resolution of enantiomers of 8, 1.