Transition Metal Boryl Complex on:
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In chemistry, a transition metal boryl complex is a molecular species with a formally 
In chemistry, a transition metal boryl complex is a molecular species with a formally anion
An ion () is an atom or molecule with a net electrical charge.
The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...
ic boron center coordinated to a transition metal
In chemistry, a transition metal (or transition element) is a chemical element in the d-block of the periodic table (groups 3 to 12), though the elements of group 12 (and less often group 3) are sometimes excluded. They are the elements that c ...
. They have the formula LnM-BR2 or LnM-(BR2LB) (L = ligand, R = H, organic substituent, LB = Lewis base
A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any sp ...
). One example is (C5Me5)Mn(CO)2(BH2PMe3) (Me = methyl). Such compounds, especially those derived from catecholborane and the related pinacolborane
Pinacolborane is the borane with the formula (CH3)4C2O2BH. Often pinacolborane is abbreviated HBpin. It features a boron hydride functional group incorporated in a five-membered C2O2B ring. Like related boron alkoxides, pinacolborane is monomeric ...
, are intermediates in transition metal-catalyzed borylation Metal-catalyzed C–H borylation reactions are transition metal catalyzed organic reactions that produce an organoboron compound through functionalization of aliphatic and aromatic C–H bonds and are therefore useful reactions for carbon–hydrogen ...
reactions.
Synthesis
Oxidative addition is the main route to metal boryl complexes. Both B-H and B-B bonds add to low-valent metal complexes. For example, catecholborane oxidatively adds to Pt(0) to give the boryl hydride. :C6H4O2BH + Pt(PR3)2 → C6H4O2B Pt(PR3)2H Addition ofdiboron tetrafluoride
Diboron tetrafluoride is the inorganic compound with the formula (BF2)2. A colorless gas, the compound has a halflife of days at room temperature. It is the most stable of the diboron tetrahalides.
Structure and bonding
Diboron tetrafluoride ...
to Vaska's complex
Vaska's complex is the trivial name for the chemical compound ''trans''-carbonylchlorobis(triphenylphosphine)iridium(I), which has the formula IrCl(CO) (C6H5)3sub>2. This square planar diamagnetic organometallic complex consists of a central iri ...
gives the triboryl iridium(III) derivative:
:2B2F4 + IrCl(CO)(PPh3)2 → Ir(BF2)3(CO)(PPh3)2 + ClBF2
References