Conformational Analysis by the Ring Current Method. The Structure of 2,2,13,13-Tetramethyl[4.4]metacyclophane

From structure to chemical shift and vice-versa

“…14) [96,97]. This approach worked for a series of cyclophanes [98,99]. Molecular modeling was used to generate different conformers, and they were subsequently evaluated using the calculated chemical shifts of the benzylic protons.…”

Facile Preparation of [4.4]Metacyclophane- and [5.5]Paracyclophane-Type Macrocycles from Arylboronic Acids and Salicylideneaminoaryl Alcohols

“…By means of dynamic NMR spectroscopy, theoretical calculations, and X-ray crystallography it has been shown that both antiperiplanar and anticlinal conformers of carbocyclic [4.4]metacyclophanes can be stable depending on the substituents on the aliphatic chain. [10] In compound 3 a the two aromatic rings are joined by two C-O-B-N chains, whereby the NÀB bond is coordinative. The NÀB bond length is 1.630(4) ä and is typical for an intermediate strength of this type of bonding.…”

Conformational Analysis of Flexible Compounds with Chemical Shift Simulation

“…The conformers A and C play an important role in the conformational equilibrium. 22 The structure of 11 in the crystalline state is identical to conformer A (Figure 6), although it is a minor contributor at room temperature and the crystals were grown at that temperature.…”