Affiliations: Inorganic Chemistry Laboratory, South Parks Road,
Oxford, OX1 3QR, UK | School of Chemistry, University of Nottingham,
Nottingham, NG7 2RD, UK | School of Chemistry, Monash University, Victoria,
3800, Australia
Abstract: The syntheses and first structural characterization of terminal
(diisopropylamino)borylene complexes are reported. The
^{11}B NMR chemical shifts for these novel systems
(δ _{B} 93.8 and 90.2 for
[Cp'Fe(CO)_{2}(BN^{i}Pr_{2})][BAr^{f}_{4}],
3, and
[CpRu(CO)_{2}(BN^{i}Pr_{2})][BAr^{f}_{4}],
4, respectively) are ca. 40 ppm downfield of those measured for the boryl
precursor complexes, consistent with observations for related trimethylsilyl
and cyclohexylamino substituted compounds. Structurally, the linearity of the M
– B – N fragment in each case and the marked shortening of the M
– B bonds (cf. the single bonds found in boryl complexes
CpFe(CO)_{2}(BN^{i}Pr_{2})Cl,
1b, and
CpRu(CO)_{2}(BN^{i}Pr_{2})Cl,
2) reflect the fact that the M – B bond order in borylene systems 3 and 4
is between one and two.
