ABSTRACT
Shape-persistent macrocycles and 3D nanocages have been prepared in one-pot under MeCN-promoted dynamic covalent bond conditions starting from silane catecholates, whose structures were confirmed by X-ray crystallography. Cation-exchange reactions of macrocycles and nanocages were performed along with the encapsulation of ammonium ions within the cavity of an anionic macrocycle and a tetrahedral nanocage.
ABSTRACT
Open-cage ketolactam fullerenes reacted with dienes on the rim of the orifice both regio- and stereoselectively. Unequivocal evidence for the structure of the Diels-Alder adduct was provided by 2D INADEQUATE 13C NMR studies on 13C enriched material, as well as via DFT-GIAO calculations. The theoretical calculations successfully model the regioselective and the endo stereoselective reaction, predicting molecular orbital control along with a repulsive steric interaction between the substituents on the nitrogen atom and those on the diene.
ABSTRACT
1,3,5-Triethylbenzene based tripodal trisilanols were synthesized. The X-ray crystal structures of trisilanols showed capsule formation as well as non-capsular network formation using silanol hydrogen bonds. The (1)H NMR and ESI-mass spectroscopy experiments for solution state binding supported encapsulation of the halide ions in the cavity of the molecular capsule with a C3 symmetry.
ABSTRACT
The isolable bishomoaromatic cation containing a heavier Group 14 element, (2,3,5-deloc)-2-phenyl-1,4,5-tris(tri-tert-butylsilyl)-1,4,5-trigermabicyclo[2.1.0]pent-2-en-5-ylium TPFPB- (2+.TPFPB-; TPFPB- = tetrakis(pentafluorophenyl)borate) was synthesized by the reaction of 5-bromo-2-phenyl-1,4,5-tris(tri-tert-butylsilyl)-1,4,5-trigermabicyclo[2.1.0]pent-2-ene (1) with [Et3Si(benzene)]+.TPFPB- in benzene at room temperature. The characteristic bishomoaromatic structure was unambiguously determined by X-ray crystallographic analysis. NMR measurements on 2+.TPFPB- confirmed the nonclassical germyl cation structure in solution and showed strong shielding of homoconjugative carbon atoms. The bishomoaromaticity in 2+ was also investigated by theoretical calculations.
ABSTRACT
The heavier group 14 element cation cluster compound, [(tBu3Si)6Ge10I]+.TTFPB- (3+. TTFPB-; TTFPB- = tetrakis(2,3,5,6-tetrafluorophenyl)borate), was unexpectedly obtained by thermolysis of in situ prepared iodocyclotrigermene, (tBu3Si)3Ge3I, in toluene in the presence of KI and K+.TTFPB-. The molecular structure of 3+.TTFPB- has been unambiguously determined by X-ray crystallography, showing that 3+ is a free germyl cation. The three "naked" cationic germanium atoms in the framework constitute a three-center two-electron (3c-2e) bond with a trishomocyclotrigermenylium character, which is well-supported by a theoretical calculation on the model compound Ge10H7+.
