Chemistry is the science of change. But why do chemical reactions take place? Why do chemicals react with each other? The answer is in thermodynamics and kinetics.In a document type is Article, the author is Daly, Scott R. and a compound is mentioned, 33100-27-5, 1,4,7,10,13-Pentaoxacyclopentadecane, introducing its new discovery. 33100-27-5
Synthesis and structural diversity of barium (N,N-dimethylamino)diboranates
The reaction of a slurry of BaBr2 in a minimal amount of tetrahydrofuran (THF) with 2 equiv of Na(H3BNMe2BH 3) in diethyl ether followed by crystallization from diethyl ether at -20 C yields crystals of Ba(H3BNMe2BH 3)2(Et2O)2 (1). Drying 1 at room temperature under vacuum gives the partially desolvated analogue Ba(H 3BNMe2BH3)2(Et2O) x (1?) as a free-flowing white solid, where the value of x varies from <0.1 to about 0.4 depending on whether desolvation is carried out with or without heating. The reaction of 1 or 1? with Lewis bases that bind more strongly to barium than diethyl ether results in the formation of new complexes Ba(H3BNMe2BH3)2(L), where L = 1,2-dimethoxyethane (2), N,N,N?,N?-tetramethylethylenediamine (3), 12-crown-4 (4), 18-crown-6 (5), N,N,N?,N?- tetraethylethylenediamine (6), and N,N,N?,N?,N?- pentamethylethylenetriamine (7). Recrystallization of 4 and 5 from THF affords the related compounds Ba(H3BNMe2BH3) 2(12-crown-4)(THF) ¡¤THF (4?) and Ba(H 3BNMe2BH3)2(18-crown-6) ¡¤2THF (5?). In addition, the reaction of BaBr2 with 2 equiv of Na(H3BNMe2BH3) in the presence of diglyme yields Ba(H3BNMe2BH3)2(diglyme) 2 (8), and the reaction of 1 with 15-crown-5 affords the diadduct [Ba(15-crown-5)2][H3BNMe2BH3] 2 (9). Finally, the reaction of BaBr2 with Na(H 3BNMe2BH3) in THF, followed by the addition of 12-crown-4, affords the unusual salt [Na(12-crown-4)2][Ba(H 3BNMe2BH3)3(THF)2] (10). All of these complexes have been characterized by IR and 1H and 11B NMR spectroscopy, and the structures of compounds 1-3, 4?, 5?, and 6-10 have been determined by single-crystal X-ray diffraction. As the steric demand of the Lewis bases increases, the structure changes from polymers to dimers to monomers and then to charge-separated species. Despite the fact that several of the barium complexes are monomeric in the solid state, none is appreciably volatile up to 200 C at 10-2 Torr. Interested yet? Read on for other articles about 33100-27-5!, 33100-27-5
Reference£º
Chiral Catalysts,
Chiral catalysts – SlideShare