Synthesis of metallomacrocyclophanes: Deduction of structure from electrospray ionization mass spectroscopy and molecular mechanics computations
摘要:
The synthesis of metallomacrocyclophanes 7-tos and 8, in which environmentally tunable ferric-catecholamide coordination bonds hold the cyclophane together, is described. W-vis spectroscopic studies of 7-tos and 8 display characteristics of ferric-tris(catecholamide) complexes, i.e. burgundy color (lambda(max) = ca. 490 nm)and high stability, at high pH, and 1:1 stoichiometry. Electrospray ionization mass spectra of 8 show prominent ions due to a monomeric 1:1 (ligand/metal) complex. Molecular mechanics calculations on 7 and 8 indicate that oar-isomeric configurations predominate, leaving a void in the metallomacrocyclophane interiors.
Synthesis of metallomacrocyclophanes: Deduction of structure from electrospray ionization mass spectroscopy and molecular mechanics computations
摘要:
The synthesis of metallomacrocyclophanes 7-tos and 8, in which environmentally tunable ferric-catecholamide coordination bonds hold the cyclophane together, is described. W-vis spectroscopic studies of 7-tos and 8 display characteristics of ferric-tris(catecholamide) complexes, i.e. burgundy color (lambda(max) = ca. 490 nm)and high stability, at high pH, and 1:1 stoichiometry. Electrospray ionization mass spectra of 8 show prominent ions due to a monomeric 1:1 (ligand/metal) complex. Molecular mechanics calculations on 7 and 8 indicate that oar-isomeric configurations predominate, leaving a void in the metallomacrocyclophane interiors.
Synthesis of trioxatricornan and derivatives. Useful keystones for the construction of rigid molecular cavities
作者:Michael Lofthagen、Russell VernonClark、Kim K. Baldridge、Jay S. Siegel
DOI:10.1021/jo00027a015
日期:1992.1
The synthesis of a new class of organic keystones for the development of macrocage structures is presented. These represent some of the most versatile building blocks for macrocage construction. The keystone structure developed herein can be interpreted as either a centrally alkylated [cd,mn]dibenzopyrene or a tris ortho-bridged triphenylmethane. We call this basic skeleton tricornan. Routes into both chiral (C3 and C1 symmetry) and achiral (C3-upsilon symmetry) derivatives are reported. The synthesis of derivatives of the trioxatricornan keystone, leading to two macrocage structures, is presented. The X-ray structures of cent-methyltrioxatricornan 7 and 2,6,10-tris(dimethylamino)-cent-methyltrioxatricornan (20) are discussed and compared to that of 1,1,1-triphenylethane. Empirical force field and AM1 calculations are compared to the X-ray structures and discussed. A general discussion on the keystone analogy is presented.