TRANSITION-METAL COMPLEXES OF SUPERSTRUCTURED CYCLIDENE MACROBICYCLES - STRUCTURAL FEATURES AND THEIR CHEMICAL CONSEQUENCES .3. CYCLIDENES WITH LONG POLYMETHYLENE BRIDGES

The syntheses and X-ray structure determinations are reported for lacunar cyclidene complexes bridged by -(CH2)9-(9) and -(CH2)10-(10) chains. Correlation of these results with those for -(CH2)8-and -(CH2)12_ bridges show how the transformations from the flat cavity increasing in width from -(CH2)3-through -(CH2)8-to the tall narrow cavity for -(CH2)12-takes place through graduated conformational changes at the nitrogen atoms to which the bridging groups are attached. These changes can also be observed in 13C NMR spectra, demonstrating that conformations are present in solution similar to those found in the solid state. Correlation of 13C chemical shift with chain length over the range -(CH2)n-(n = 3–10, 12) shows that some resonances are strongly influenced by cavity width. Other resonances show a small-scale alternation between n-odd and n-even, associated with the distortions required in bridges formed from even-membered chains. Crystal data: C29H50N6P2F12Ni.C3H6O (9), triclinic, PĪ, a = 11.298 (6) Å, b = 13.615 (9) Å, c = 14.608 (10) Å, α = 75.48 (5)°, β = 73.32 (5)°, γ = 73.56 (5)°, Z = 2; C30H52N6-P2F12Ni.C2H3N (10), orthorhombic, P212121, a = 10.221 (4) Å, b = 13.723 (11) Å, c = 29.255 (16) Å, Z = 4. © 1990, American Chemical Society. All rights reserved.