Conformational behavior of symmetrical and unsymmetrical mono(alkynylpeptide)-tungsten complexes

► Alkynylpeptides were synthesized and were reacted with tungsten to form monoalkyne complexes. ► The resulting monoalkyne complexes display relatively rapid rotation about the tungsten-alkyne bond. ► The peptides in a series of symmetrical alkynylpeptides adopt an extended conformation in solution.