organic compounds
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The title compound, C34H34, systematic name 9,9,9′,9′-tetraethyl-2,2′-bi(9H-fluorene), crystallized with two crystallographically independent molecules (A and B) in the asymmetric unit. These differ mainly in the orientation of the lateral ethyl chains: in molecule A, they are both on the same side of the molecule whereas in molecule B, one diethylfluorene moiety has undergone a 180° rotation such that the two pairs of ethyl residues appear on opposite sides of the molecule. The fluorene ring systems subtend dihedral angles of 31.37 (4) and 43.18 (3)° in molecules A and B, respectively. Hence the two fluorene moieties are tilted slightly toward one another. This may be due to the presence of intermolecular C—Hπ interactions between neighboring molecules. The lateral ethyl chains (excluding H atoms) are also almost planar, with each pair almost perpendicular to the plane of the fluorene system to which they are attached with dihedral angles between the ethyl and fluorene planes in the range 86.04 (8)–89.5 (1)°.
metal-organic compounds
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In the title polymeric complex, {[Ag(C11H11N3)]PF6}n, the AgI ion is two-coordinated in a nearly linear coordination geometry [N—Ag—N = 175.98 (9)°] by two pyridine N atoms from two symmetry-related N-[(pyridine-2-yl)methyl]pyridine-3-amine ligands. Each AgI ion is bridged by the ligands, forming a helical chain propagating along the b-axis direction. The right- and left-handed helical chains are alternately arranged via AgAg [3.2639 (5) Å] and π–π stacking interactions [centroid–centroid distance = 3.523 (1) Å], resulting in the formation of a two-dimensional supramolecular network extending parallel to (101). Weak AgF interactions [longest AgF interaction = 3.153 (2) Å], as well as N—HF and C—HF hydrogen-bonding interactions, occur between the helical chains and the anions.
research communications
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The reaction of AgI with the unsymmetrical ligand N-(pyridine-2-ylmethyl)pyridine-3-amine afforded right- and left-handed helical chains. The AgI atom of the right-handed helical chain adopts a slightly distorted linear coordination geometry, while that of the left-handed helical chain displays a bent geometry.