Apparent shortening of the Csp3—Csp3 bond analysed via a variable‐temperature X‐ray diffraction study in racemic 1,1′‐binaphthalene‐2,2′‐diyl diethyl bis(carbonate)

Crystal structure determination at room temperature 292 (2) K] of racemic 1,1′‐binaphthalene‐2,2′‐diyl diethyl bis(carbonate), C₂₆H₂₂O₆, showed that one of the terminal carbon–carbon bond lengths is very short Csp³—Csp³ = 1.327 (6) Å]. The reason for such a short bond length has been analysed by collecting data sets on the same crystal at 393, 150 and 90 K. The values of the corrected bond lengths clearly suggest that the shortening is mainly due to positional disorder at two sites, with minor perturbations arising as a result of thermal vibrations. The positional disorder has been resolved in the analysis of the 90 K data following the changes in the unit‐cell parameters for the data sets at 150 and 90 K, which appear to be an artifact of a near centre of symmetry relationship between the two independent molecules in the space group P at these temperatures. Indeed, the unit cell at low temperature (150 and 90 K) is a supercell of the room‐temperature unit cell.