Describe how alkane complexes of d metals have been unambiguously identified by NMR. What additional insights can be gained from X-ray diffraction? See S. Geftakis and G.E. Ball, J. Am. Chem. Soc., 1998, 120, 9953; W.H. Bernskoetter, C.K. Schauer, K.I. Goldberg, and M. Brookhart, Science, 2009, 326, 553; and S.D. Pike, A.L. Thompson, A.G. Algarra, D.C. Apperley, S.A. Macgregor, and A.S. Weller, Science, 2012, 337, 1648.