doi:10.1002/recl.19070260803single-crystal X-ray studyT=298 Kmean sigma(C-C)=0.004 angstromR factor=0.037wR factor=0.101data-to-parameter ratio=12.7First page of articleBöeseken, J.John Wiley & Sons, Ltd.Recueil des Travaux Chimiques des Pays-Bas...