Electrochemical, spectroscopic, and structural evidence for the mild hydrolysis of tetracyanoethylene, TCNE, to form the 2,3,3-tricyanoacrylamidate ligand: Isolation of an unexpected quadruply-bonded polymeric material [Mo 2(O2CCMe3)3((NC) 2CC(CN)CONH)]∞
Résumé
Under strictly anhydrous conditions, no reaction occurs between Mo 2(O2CCMe3)4 and tetracyanoethylene, TCNE, at room temperature, but after addition of 1 equiv of water, a reaction proceeds to form [Mo2(O2CCMe3) 3((NC)2-CC(CN)CONH)], 1. The compound contains a quadruple-bonded Mo2 unit and the 2,3,3-tricyanoacrylamidate anion as a ligand (TC3A), a very unusual hydrolyzed form of TCNE. Two different solid-state structures were obtained after crystallization of 1. Crystals obtained from CH2Cl2 consist of a two-dimensional network, and crystals grown from a C6H6 solution form a 1-D chain motif. In both cases, the TC3A ligand acts as a polydentate ligand involving a bidentate OCN bridging unit and two CN groups. The electrochemical and spectroscopic (IR, UV/vis/near-IR, NMR, EPR) properties of 1 support the formulation in solution as a discrete 1:1 complex of the TC3A donor ligand and a Mo2 unit with no charge transfer. The coordinated TC3A ligand exhibits redox properties similar to those of free TCNE.
Mots clés
2
3
3 tricyanoacrylamidate ligand
acrylamide derivative
ligand
polymer
tetracyanoethylene
unclassified drug
article
chemical bond
chemical structure
crystallization
electrochemical analysis
hydrolysis
oxidation reduction reaction
polymerization
reaction analysis
room temperature
solid state
spectroscopy
structure analysis