Is the C-Mo Bond in a Small Molybdenum Methylidyne Really a Triple Bond?

Oxidative scission of a Mo-Mo quadruple bond.

Two compounds containing the cations Mo2(DPhIP)4n+, n = 1 or 2 and DPhIP = the anion of 2,6-diphenyliminopiperidine, have been obtained by oxidation of the quadruply-bonded Mo2(DPhIP)4 species. The first oxidation process conserves the structure but results in a slight increase of the Mo-Mo distance from 2.114(1) to 2.136(2) A in [Mo2(DPhIP)4](PF6).2CH2Cl2 (1.2CH2Cl2). However, the second oxida...

Rotational barrier of a molybdenum-molybdenum quadruple bond.

The synthesis and characterization of molybdenum(II) porphyrin dimers containing unbridged metal-metal quadruple bonds are presented. Variable temperature 300 MHz (1)H NMR studies of meso-substituted derivatives provide novel solution evidence for both the existence of quadruple bonds and for a barrier to rotation about the metal-metal bonds in these complexes. The activation energy for this ro...

Interaction of a C-F bond with the π-system of a C═C bond or "head on" with a proximate C-H bond.

We describe the synthesis and preliminary study of two molecules, in which a fluorine atom is positioned proximately above the π-orbitals of a C═C bond or else wherein a C-F bond interacts in a "head on" fashion with a proximate C-H bond. The spectroscopic characteristics of these unusual interactions are documented, X-ray crystallographic analyses are reported, and theoretical calculations are...

Disilyne with a silicon–silicon triple bond: A new entry to multiple bond chemistry*

The synthesis, crystal structure, and characterization of a silicon–silicon triply bonded species, disilyne with two bis[bis(trimethylsilyl)methyl]isopropylsilyl substituents, are described. The nature of the sp-hybridized silicon atoms is discussed from the viewpoint of spectroscopic results and theoretical calculations. The reactivity of the disilyne with alkali metals, tBuLi, and π-bonded co...

A versatile ruthenium catalyst for C-C bond formation by C-H bond activation.