名称:
Synthesis of [3(5)]Adamanzane, 1,5,9,13-Tetraazabicyclo[7.7.3]nonadecane, by Oxidative C--N Cleavage of [3(6)]Adamanzane, 1,5,9,13-Tetraazatricyclo[7.7.3.3(5,13)]docosane and Crystal Structure of the Tetraprotonated Bromide Salt of [3(5)]Adamanzane.
摘要:
Reaction of the cage amine [3(6)]adamanzane, 1,5,9,13-tetraazatricyclo-[7.7.3.3(5,13) ]docosane, with sodium iodide in 93% sulfuric acid affords the bicyclic tetraamine [3(5)]adamanzane, 1,5,9,13-tetraazabicyclo[7.7.3]nonadecane which was isolated as its tetraprotonated bromide salt, [H-4[3(5)]adz]Br-4 (yield 70%). The structure of the [H-4[3(5)]adz]Br-4 has been determined by X-ray diffraction techniques at T=120 K; M-r=529.09, monoclinic, P2(1)/n, a=11.300(3), b= 12.563(3), c = 15.561(6)Angstrom A, beta = 90.29(3)degrees, Z = 4, D-x = 1.78gcm(-3) MoK alpha = 0.71073 Angstrom A, mu = 72.9 cm(-1) F(000) = 1176, R(F) = 0.0734 for 4028 reflections with I > 2 sigma(I) and wR(k(2)) = 0.2116 for all 6439 unique reflections. The conformation of the 16-membered ring is best described as a distorted "rectangular" [3535] conformation. The distance between the bridging nitrogen atoms is 4.983(9) Angstrom A, and the distance between the non-bridging nitrogen atoms is 7.568(10) Angstrom A. The four acidic hydrogen atoms are all oriented away from the cavity. The concentration acid dissociation constants of H-4[3(5)]adz(4+) were determined by potentiometric glass-electrode measurements and H-1 and C-13 NMR spectroscopy:PKa1 = 1-2, pK(a2)= 1-2, pK(a3) = 9.65(2) and pK(a4) = 12.09(4) (1 M NaBr, 25 degrees C).