Anisotropic phase rebuilding I Waste preventionGadsolid reactions of acetone vapor with neutral organic compounds, salts, or host crystals with strict exclusion of solvents are reported. This gas/solid technique largely avoids waste formation and saves resources, Starting hydrochlorides or hydrobromides are also synthesized by gadsolid techniques. Dihydrohalides of o-phenylenediamines give 1,5-benzodiazepines 3, aromatic and aliphatic 1,2-aminothiols (oaminothiophenol, penicillamines, cysteine) yield five-membered thiazolines and thiazolidines 7, 9, 11, 13. Virtually all carbonyl reagents of the primary amino type 14 give quantitatively the imino derivatives 15 and water. Salt formation may be helpful for increasing melting points and sometimes reactivity as in 8, 10, and 12 if surface passivation has to be overcome. In the case of solid 14 the free bases react equally well. Acetone (2) may be quantitatively removed from exhaust gases by using hydroxylaminium phosphate with formation of free acetone oxime at high flow rates. Inclusion of acetone into various hosts (17-20, but not 16) is more efficient by imbibition from the gas phase than by crystallization from acetone as the solvent. This advantage may be utilized for gas separations. Some further gases (vapors) coexist in imbibed clathrates whereas others do not. The mechanisms of the gadsolid reactions are elucidated using atomic force microscopy (AFM). Phase rebuildings involve anisotropic movements of molecules over large distances and the formation of characteristic features. In some cases surface hydrates catalyze the gadsolid reaction. Solid-state mechanisms for imbibition from the gas phase into host crystals with formation of clathrates are similar in nature to those of the covalent reactions. These results are correlated with known X-ray crystal structures where available.
Mn-N bond lengths (2.406(4) A). As expected with a higher coordination number, Mn to ligand bonds are considerable longer than those of six-coordinate Mn" complexes, but are similar to those found in the square-antiprismatic complex, [Mn(cyclen),12 + (2.384-2. 435 (cyclen = 1,4,7,10-tetraazacyclododecane). The only other examples of discrete bipyridine-N,N'-dioxide) and (Et,N),~(NCS),]. ["] The great flexibility of the [2. 6.872 A in the empty ~r y p t a n d . [~~~ The metal has induced a twisting of the ligand about the triad resulting in an oblique (ob) arrangement of the C3-C3' groups compared to the parallel (leg configuration of the cryptand and cryptates of larger cations. This creates a chiral dication which is isolated as a racemic mixture in a centrosymmetric space group. The large change in ligand conformation compared to the uncomplexed cryptand and lack of crystal field stabilization energy for a high-spin d5 Mn"suggests that there is little kinetic stability to this complex. Yet the complex is stable in anhydrous acetonitrile where its solution EPR spectrum is distinct from that of Mn(CF,SO,),A pure powder of 1 exhibits a broad signal at g = 2.03, although powder and orientated single-crystal samples of 1 in a diamagnetic matrix (1 YO in [Cd c [2.2.2]cryptand] (CF,S03),)1251 exhibit well-resolved multiline axial spectra with a small zero-field splitting, D = 220 gauss (Fig. 3). Experimental ProcedureThe triflate salt of 1 is isolated as colorless, analytically pure.'26' crystallographic q~ality.'~" hexagonal plates in 80% yield, by diffusing diethyl ether into an anhydrous acetonitrile solution of an equimolar mixture of Mn(CF,SO,), . 2CH,CN and the ligand under a dry, dinitrogen atmosphere. 3) the addition of radical^."^ Because C,, is a polyfunctional molecule, a myriad of products is formed after treatment with an excess of a reagent, for example a nucleophile.[61 It is impossible to isolate isomerically pure single compounds from such reaction mixtures. To control nucleophilic additions to only one double bond in C,, and to maximize the yield of the monoadducts, we titrated dilute solutions of C,, in toluene with tert-butyllithium and ethylmagnesium bromide. The concentrations of C,, , the monoaddition product, and higher addition products upon addition of the nucleophile was determined quantitatively by high-pressure liquid chromatography (HPLC). For this purpose the initially formed fullerides were protonated with methanolic HC1 to give C,,HtBu 1 and C,,HEt 2 (Scheme 1). In this way the formation of products and the consumption of C,, could be followed very closely from the calculated peak areas (Fig. 1). The UVjVIS spectrum of each peak was simultaneously recorded by means of diode array scans (200-500 nm) allowing the unambiguous assignment of the HPLC peaks to the compounds based on their optical spectra. Because other anionic nucleophiles like amides, hydrides, alkoxides, and thiolates react similarly with C,, this synthetic method should allow access to a large variety of monofuncti...
Dimethylphenol durch Veresterung und intramolekulare Arylkupplung synthetisieren l a~s e n [~~. Die Ergebnisse der Ringoffnungsexperimente sind in Tabelle 1 zusammengefaat.Die Leistungsfahigkeit des Verfahrens zeigt sich in den schon mit den monocyclischen Derivaten 3a-c erzielten guten Ergebnissen, vor allem aber in den zum Teil exzellenten Atropisomerenverhaltnissen mit den bicyclischen Reagentien 4a-c, die bei praktisch quantitativem Umsatz durchweg bei mindestens 90: 10 liegen. Dabei wurden die mit Abstand hochsten asymmetrischen Induktionen, unabhangig vom verwendeten Lacton, rnit den B-Methyl-und B-n-Butyl-Derivaten 4b und 4c erhalten.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.