During the work on my diploma thesis I was trained to be a x-ray crystallographer by Prof. Dr. P. G. Jones, Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig. The topic of the thesis were x-ray crystallographic studies on coordination and molecule compounds of the heavier main group elements; full (german) title: Röntgenstrukturuntersuchungen an Koordinations- und Molekülverbindungen der schwereren Hauptgruppenelemente. [Download]
The following illustration shows an typical example, an phosphanyl-substituated alkyl(amino)carben complex from the chromium triade.
A section from the crystal structure of N,N‘-[(Pentamethyl-2,4-cyclopentadiene-1-yl)phosphandiyl]bis{[amino(4-chlorophenyl)methylene]pentacarbonyltungsten(0)} (ROHKOST). This compound can be described as an dinuclear amino(aryl)carben of the FISCHER type, where the phosphanyl part resembles a bridge element. (R. STREUBEL, U. ROHDE, J. JESKE, F. RUTHE, P. G. JONES, Eur. J. Inorg. Chem., 1998, 2005-2012.)