Tricarbonyl[N,N′,N′′-tris(2,6-diisopropylphenyl)guanidine]molybdenum(0)

Abstract

In the title compound, [Mo(C37H53N3)(CO)3], the Mo atom to ring-centroid distance in the η6-coordinated tricarbonyl­molybdenum group is 1.958 (1) Å. The three C O groups are pseudo-octa­hedrally disposed with C—Mo—C angles ranging from 80.7 (1) to 87.4 (1)°. The two uncoordinated 2,6-diisopropyl­phenyl-substituted benzene rings form dihedral angles of 75.96 (8) and 78.01 (9)° with the mean plane of the guanidine group. The coordinated benzene ring is in a slight sofa conformation with the N-substituted C atom and the bonded N atom dispaced by 0.090 (3) and 0.458 (4) Å, respectively, from the mean plane of the remaining ring atoms. In the crystal, despite there being two N—H donor groups, no conventional hydrogen bonds are present. This may be because of the steric effects of the bulky diisopropyl­phenyl groups.

Are Monophospha(III)amidines and ‐guanidines with Ionizable Hydrogens Tautomeric? Towards a Deeper Understanding of Two Related Hetero‐element Functional Groups

“…) [53] At the current time we have not been able to study these dynamic effects in 4 in greater detail, but the lack of effect on the NH resonance at RT is consistent with slowed rotation about the P−C single bond; the two longer P−C (P−C Dipp and P−C guan ) bonds should also lead to lower barriers for rotation compared with the N−C bonds. Slow rotation of the “backbone” substituent was also attributed to the Mo(CO) 3 “piano‐stool” complex of DippN=C{NHDipp} 2 , further supporting our hypothesis [53,73] …”

“…Slow rotation of the "backbone" substituent was also attributed to the Mo(CO) 3 "piano-stool" complex of DippN=C{NHDipp} 2 , further supporting our hypothesis. [53,73]…”