Organometallic complexes for non-linear optics XII. Syntheses and second-order susceptibilities of (neomenthyldiphenylphosphine) gold σ-arylacetylides: X-ray crystal structures of Au( C≡CPh) (nmdpp) and Au((E)-4,4′-C≡CC₆H₄CH=CHC₆H₄NO₂)(nmdpp)

The series of complexes Au(C≡CR)(nmdpp) (R = Ph (2), 4-C₆H₄NO₂ (3), 4,4′-C₆H₄C₆H₄NO₂ (4), (Ε)-4,4′-C₆H₄CH=CHC₆H₄NO₂ (5), (Ζ)-4,4′-C₆H₄CH=CHC₆H₄NO₂ (6), 4,4′-C₆H₄C≡CC₆H₄NO₂ (7), 4,4′-C₆H₄N=CHC₆H₄NO₂ (8); nmdpp = (+)-neomenthyldiphenylphosphine) has been synthesized by reaction of AuCl(nmdpp) with the corresponding acetylene and methoxide in the presence of trace amounts of a phosphine oxide, and complexes 2 and 5 have been structurally characterized. Complexes 2-8 and analogous (triphenylphosphine)gold acetylides and precursor (phosphine)gold chlorides have been examined for their second-order bulk susceptibilities χ⁽²⁾ by the Kurtz powder technique, with the largest response (ca. 2 × urea) being that from 3.