In problems 4.28 to 4.51, refer to Table 4.3 for isotopic abundances where needed.

The compounds Se_nS_8–n with n = 1–5 are structurally similar to S₈. Structure 4.19 shows a representation of the S₈ ring (it is actually non-planar) and the atom numbering scheme; all the S atoms are equivalent. Using this as a guide, draw the structures of SeS₇, 1,2-Se₂S₆, 1,3-Se₂S₆, 1,2,3-Se₃S₅, 1,2,4-Se₃S₅, 1,2,5-Se₃S₅ and 1,2,3,4-Se₄S₄. How many signals would you expect to observe in the ⁷⁷Se (I = 1/2, 7.63%) NMR spectrum of each compound?

Table 4.3

Transcribed Image Text:

8 S 7 S 12 S-S S- 6 -S 5 (4.19) S 3 S4