Substituted Boranes, RBH2 and R2BH

Data for the Generation of RBH2 and R2BH from the Corresponding Lithium Organylhydrobor-ates [1]. 

The reaction is presumed to proceed via a rapid formation of CH3BH2 monomer, followed by an even more rapid monohydroboration. The second stage is slower, possibly due to a slower formation of the R(CH3)BH monomer, or a relatively slow reaction of this monomer, or both [3]. 

Chemiluminescence has been observed in the oxidation of certain disubstituted organobor-anes. The reaction of diisopinocampheylborane or 9-borablcyclo[3.3.1]nonane with O2 in tetrahydrofuran leads to relatively bright chemiluminescence (ca. 2x10 photons s mL mol- ). The B-H infrared spectral modes disappear during the process, and 0-H and C=0 modes appear. The introduction of a galvinoxyl radical scavenger leads to a simultaneous drop in chemiluminescence and in O2 absorption [7]. 

The out-of-plane bending fundamental V4 (near 926 cm ) was recorded at high resolution in the infrared spectrum of HBF2 [8]. Rotational and centrifugal distortion constants were obtained for the two isotopic species H BF2 and H BF2 in both the ground and 4 levels the position of the Vg fundamental of was estimated to be 1099 cm from rotational 

A comparison of the energies of double bonds between second row elements and carbon or silicon included the species H2C=BH and H2SI=BH. The latter s double bond is weaker than that of the former the 7c-bonding energies are found to be 53.7 and 27.0 kcal/mol, and the computed bond distances are 1.377 and 1.819 A, respectively [13]. 

---