Chapter 14, Problem 14.24E

Which of the following molecules should have pure rotational spectra?

(a) Dimethyltriacetylene, ${\text{H}}_{\text{3}}\text{C}-\text{C}\equiv \text{C}-\text{C}\equiv \text{C}-\text{C}\equiv \text{C}-{\text{CH}}_{\text{3}}$

(b) Cyanotetraacetylene, $\text{H}-\text{C}\equiv \text{C}-\text{C}\equiv \text{C}-\text{C}\equiv \text{C}-\text{C}\equiv \text{C}-\text{C}\equiv \text{N}$

(Such molecules have been detected in intersteller space.)

(c) Nitric oxide, $\text{NO}$

(d) Nitrogen dioxide, ${\text{NO}}_2$

(e) Sulfur tetrafluoride, ${\text{SF}}_{\text{4}}$

(f) Sulfur hexafluoride, ${\text{SF}}_6$