(17 points) Calculate the lowest energy ? for a solution of [Cr(en)2F2]+ that has absorption bands at 17500 cm1, 23000 cm1 and 27500 cm. Make sure you show all work. Solution In the given complex there is Cr 3+ ion, it has d3 electronic configuration and it has 4 F as ground state term. In octahedral complex this term will be splitted into three terms they are A2g, T2g and T1g. Among the three terms A2g is ground state term. It is singlet and lowest energy electronic transition corresponding to A2g ............> T2g which requires 17500 cm-1. This energy is equal to energy gap between two sets of orbitals of Cr^3+ in octahedral complex. So this energy is equal to crystal field splitting energy of the complex. Hence delta o = 17500 cm -1 .