Solution *H NMR spectrum

From these studies of aryllithium complexes, it can further be concluded that the quadrupolar interaction is a very sensitive indicator of the type of aggregation and solvation state. In certain cases the /-value ranges overlap, but additional investigations can often easily clarify the ambiguity, such as the ligand/metal ratio. The latter can, for example, be determined by a solution H NMR spectrum of the solid material in a suitable solvent. 

The solution H NMR spectrum of K(18-crown-6 PtCl3(t) -MeC=CMe) exhibits a singlet at 3.60 and a pseudo-triplet at 2.11 (/ 32.8 Hz). Assign the signals and explain the origin of the pseudo-triplet . Sketch the pseudotriplet and show where the coupling constant of 32.8 Hz is measured. 

The reaction of 1,3-dimethylimidazolium iodide (shown below) with one equivalent of KO Bu in THF, followed by addition of one equivalent of Ru3(CO)i2 leads to product A. The IR spectrum of A has several strong absorptions between 2093 and 1975 cm", and the solution H NMR spectrum of A exhibits singlets at 6 7.02 and 3.80 ppm (relative integrals 1 3). (a) What role does KO Bu play in the reaction (b) What is the likely identity of A (c) Draw a possible structure of A and comment on possible isomers. 

The room temperature, solution H NMR spectrum of A showed the following signals 6 4.90 (s, 2H),... 

The reaction of (t -Cp)(r -C5H4l)Fe with BuLi followed by treatment with half an equivalent of ZnBr2 gave compound A. This was immediately reacted with hexaiodobenzene to yield B, the mass spectmm of which showed a parent ion at m/z -1182. The solution H NMR spectrum of B exhibited three signals /ppm 4.35 (m, 12H), 4.32 (m, 12H), 3.99 (s, 30 H). In the C H NMR spectrum of B, five signals were observed. Deduce the structure of B, and rationalize the observed NMR spectroscopic data. Suggest a structure for compound A. 

---