Vibrational spectroscopic study of trimethylarsine–boron trihalide adducts
Abstract
The vibrational spectra of AsR3·10BX3(R = CH3 or CD3; X = Cl or Br) and AsR3·nBX3(R = CH3 or CD3; X = Cl, Br, or l; n = natural abundance) are reported. The BAs stretching frequencies are assigned between 640 and 740 cm–1, and the calculated force constants (2.84, 2.26, and 1.70 mdyn A–1) show that the BAs bond strength decreases for the adducts in the sequence Bl3 > BBr3 > BCl3. The order of BAs bond strength is the same as that of the adduct stabilities as determined by calorimetry.