The molecular fragment, P2H, has the non-linear structure shown below: (i) What is the point group of this molecule? (ii) The P-H stretching vibration is observed at 2314cm1 in the IR spectrum of P2H. If the hydrogen atom is replaced by deuterium, predict the position of the P-D stretching vibration, explaining any assumptions you make in your answer. (iii) Sketch and describe all of the normal mode vibrations of P2H. Predict, with reasoning, whether or not each mode is IR active. Phosphine, PH3, has recently been detected in clouds in the upper atmosphere of the planet Venus using pure rotational spectroscopy. (i) Given that phosphine has a structure similar to that of ammonia ( NH3), explain why phosphine is suitable for recording a pure rotational spectrum. (ii) Only a single rotational transition, from J=0 to J=1, was detected from PH3