Question

Use the localized σ/delocalized π approach to develop a bonding scheme for the thiocyanate anion SCN– . Include each of the steps described in question 7. What are the S-C and C-N bond orders? Do your results agree with the Lewis structure(s) for this species?

Answer 1

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In diagrams, contributing structures are typically separated by double-headed arrows (). The arrow should not be confused with the right and left pointing equilibrium arrow (). All structures together may be enclosed in large square brackets, to indicate they picture one single molecule or ion, not different species in a chemical equilibrium.

Alternatively to the use of resonance structures in diagrams, a hybrid diagram can be used. In a hybrid diagram, pi bondthat are involved in resonance are usually pictured as curves ^[13] or dashed lines, indicating that these are partial rather than normal complete pi bonds. In benzene and other aromatic rings, the delocalized pi-electrons are sometimes pictured as a solid circle.

S=C and C=N have bond orders of 2,and C≡N has abond order of 3