Self-assembly of the selenium-bridged novel metallacyclophanes [{(CO)3Re(μ-SeR)2Re(CO)3}2(μ-L)2] (1–3) has been accomplished by treating diaryl diselenide with low-valent transition-metal carbonyl and rigid bidentate azine ligands under one-pot reaction conditions. The oxidative addition of diphenyl/dibenzyl diselenides to Re2(CO)10 with 4,4′-bipyridine, trans-1,2-bis(4-pyridyl)ethylene, and 1,4-bis[2-(4-pyridyl)ethenyl]benzene afforded tetranuclear metallacyclophanes. These compounds have been characterized by elemental analysis and IR, NMR, and UV–vis absorption spectroscopic techniques. The molecular structures of metallacylophanes 1a,b and 2 were determined by single-crystal X-ray diffraction methods, and the crystal structures showed that two selenium-bridged dirhenium metallacycles were linked by two bipyridyl spacers and attained a framework of molecular rectangles. In addition, the molecular recognition capabilities of the molecular rectangles 1a,b and 2 with aromatic compounds such as pyrene and triphenylene have been investigated by studying their binding properties, using UV–visible absorption and fluorescence emission spectrophotometric methods. The nature of the binding interactions were further supported by single-crystal X-ray diffraction methods, and the crystal structures of 1 b·(pyrene) and 1 b·(triphenylene) revealed that CH···π interactions are mainly responsible for the binding of 1b with pyrene and triphenylene.

No abstract

No abstract

The title compound, [Re2(C6H5Te)2(CO)8], crystallizes with two mol­ecules in the asymmetric unit, in which two Re atoms are coordinated in a slightly distorted octa­hedral environment and are bridged by two Te atoms, which show a distorted trigonal-pyramidal geometry. The torsion angles for the Te—Re—Te—Re sequence of atoms are 19.29 (18) and 16.54 (16)° in the two mol­ecules. Thus, the Re—Te four-membered rings in the two mol­ecules deviate significantly from planarity. Two intra­molecular C—H⋯O inter­actions occur in one of the mol­ecules. Te—Te [4.0551 (10) Å] inter­actions between the two mol­ecules and weak inter­molecular C—H⋯O inter­actions stabilize the crystal packing.

In the title complex, [Re2(C6H5Te)2(C11H9N)(CO)7], two Re atoms are coordinated in slightly distorted octa­hedral coordination environments and are bridged by two Te atoms, which are coordinated in trigonal-pyramidal environments. The torsion angle for the Te—Re—Te—Re sequence of atoms is 17.06 (3)°. The crystal structure is stabilized by weak C—H⋯O and C—H⋯π inter­actions. In addition, there are Te⋯Te distances [4.0392 (12) Å] and O⋯O distances [2.902 (19) Å] which are shorter than the sum of the van der Waals radii for these atoms. A short inter­molecular lone pair⋯π distance [C O⋯Cg = 3.31 (2) Å] is also observed.