Single crystal X-ray diffraction studies of aromatic oligomers: resolution of the bond-angle anomaly in poly(aryletherketone)s

Self-Assembling Supramolecular Daisy Chains

“…One of the pyridinium rings of the dication is oriented orthogonally to the resorcinol ring of the macrocyclic polyether. This ªedge-to-faceº geometry results in a marked distortion in the external angles at the C-5 position on the resorcinol ring of about AE 68; a deformation directly analogous to that observed [9] in diphenyl ethers. Intracomplex stabilization is achieved by p ± p stacking between the bipyridinium ring systems and their sandwiching p electron rich aromatic ring systems.…”

“…X-Ray structural analysis [7] on one of these crystals (Figures 3 and 4) reveals that, in the solid state, pairs of 6 2 dications interweave with each other to form a C 2 -symmetric homodimeric pair. This ªedge-to-faceº geometry results in a marked distortion in the external angles at the C-5 position on the resorcinol ring of about AE 68; a deformation directly analogous to that observed [9] in diphenyl ethers. One of the pyridinium rings of the dication is oriented orthogonally to the resorcinol ring of the macrocyclic polyether.…”

“…This observation is encouraging in the face of the challenge to synthesize acyclic [a I ]daisy chain supermolecules en route to the preparation of mechanically interlocked polymers in the shape of macromolecular daisy chains. To achieve this objective, we wished to take advantage of the self-assembly of multidentate ligand precursors with transition metal centers [5] which, in the hands of Fujita, [6] Stang, [7,8] and others, [9] has led to the formation of some spectacular molecular architectures consisting of multinanometer-sized polynuclear molecular squares and three-dimensional molecular objects. Chem.…”

“…[4] The properties of these C 60 hybrids are encouraging and have generated our interest in the construction of even more complex two-and three-dimensional systems. To achieve this objective, we wished to take advantage of the self-assembly of multidentate ligand precursors with transition metal centers [5] which, in the hands of Fujita, [6] Stang, [7,8] and others, [9] has led to the formation of some spectacular molecular architectures consisting of multinanometer-sized polynuclear molecular squares and three-dimensional molecular objects. [10] Here, we report the synthesis and X-ray crystal structure of the fullerene-containing rigid dinuclear cyclophane 1 which is obtained by self-assembly of the novel fullerene ligand 2 with Pt II centers.…”

Effect of Differences in the Backbone Chemical Environment of Carbonyl and Ether Groups in Poly(aryl ether ketones) on Crystallographic Parameters

“…Poly(aryl ether ketone) high performance engineering plastics and matrix resins have attracted considerable interest in the recent decade because of their high yield stress, ductile behavior, other mechanical properties, and stability at high temperature. , Many authors have investigated their crystal structure and lattice parameters. − Dawson and Blundell 3 first reported X-ray data of PEK and PEEK, and found that PEK and PEEK have a unit cell and chain conformation similar to that of poly(phenylene oxide), which suggested that the crystal structure of poly(phenylene oxide) was also a good model for aryl ether ketone polymers. From then on, almost all researchers have accepted the conclusions that poly(aryl ether ketones) have an orthorhombic unit cell and ether and ketone linkages can be interchanged with only a minimum of distortion.…”