Question

Raman spectrum of an adduct. Help quick. When it says references it just means that you should look at them, but don’t need to cite them necessarily. Thank you.

References:

KC Nainan and GE Ryschkewitsch, Inorg. Chem., 1969, volume 8, 2671-2674

KB Harvey and NR McQuaker, Can J Chem, 1971, volume 49, 3272-3281

MA Frisch, HG Heal, H Mackle and IO Madden, J. Chem Soc., 1965, 899-907

9. Raman vibrational spectrum of PPhs BHs. The same basic information is observed in the infrared spectrum (however our infrared spectrometer cannot observe peaks below 650 cm2). 102740 1104 1131 1160 13 1182 11 1309 1333 1433 1478 424 439 476 26 50 504 605 616 623 702 40 10 30 76611572 16 1585 54 20 919 10 999 101 0 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 500 400 Wavenumbers (cm1) What key the (B.D covalent bond in PPh3 BHs? Consult the provided references. absorption peaks in the Raman spectrum above allow for the unequivocal proof of 52

Answer 1

In the given spectrum peak at 476cm-1 gives the proof of B-P covalent bond.

As per the reference ,the polar B-P Covalent bind absorbs at 556 cm-1 in substituted PR3•BR3 but due to the replacement of R with H the bond length increased and the wavelength decreased to 476 cm-1.