X-Ray structural investigations of a bisparaphenylene-34-crown-10 derivative (BPP34C10) and its 1 : 1 : 1 complex with [Diquat][PF& and H20 reveal that, of two crystallographically independent conformations (I and II) both supporting large molecular cavities, one (11) retains its gross shape on complexation and interacts with the [Diquat]2+ dication by means of hydrogen and electrostatic bonds whilst accommodating weak charge transfer interactions and a hydrogen bonded H 2 0 molecule within the docking constraints and microcavity, respectively, imposed by the more dominant non-covalent forces.Greatly encouraged by the observation1 that BMP32ClO-t is capable of complexing with [Paraquat][PF&,t as well as with [Diquat][PF6I2,1-by virtue of a combination2 of electrostatic t The structural formulae for BMP32C10 and for [Paraquat][PF& and [Diquat][PF& are illustrated in the two preceding communications (refs. 1 and 2). The structural formula for the bisparaphenylene-34-crown-10 derivative (BPP34C10) is numbered with reference to its systematic name,

Q , and L 4 R were then used to synthesize some novel mono-and binuclear ruthenium(ii), rhenium(i), silver(i), and copper(i) complexes, which were characterized by mass spectrometry, NMR spectroscopy, and, where possible, X-ray crystallography. The absorption spectra, luminescence properties, and electrochemical behavior of the L 2 . None of the complexes studied emits at room temperature, because the potentially luminescent MLCT excited state undergoes electron-transfer quenching by the paraquat-type units in the ligands. In a rigid matrix at 77 K, where electron transfer cannot occur, emission is observed from the complexes containing the cyclophane ligands L 8 ) that can be assigned to i) reduction of the paraquat-and bpytype moieties of the ligands, ii) reduction of the bpy ligands (in the Ru complexes), iii) oxidation of the metals, and iv) oxidation of the dioxynaphthalene units of the crown ether (in complexes containing the catenane ligand).

X-Ray crystallography on the free BPP(3n+4)Cn ethers where n = 7, 8, 10, 11, and 12 reveals a conformational dependence for the macrocycles which is reflected in their cavity sizes, with a maximum for n = 10, and in the relative orientations of the two hydroquinol rings, almost orthogonal for n = 7 and parallel or nearly parallel for n = 8, 10, 11, and 12, with respect to each other.

Macrocyclic polyether‐diester compounds have been prepared by reacting oligoethylene glycols with the appropriate dimethyl esters in the presence of catalytic amounts of alkali metal methoxides. The methanol by‐product was removed by molecular sieves. Product yields were improved for the preparation of all macrocyclic compounds except a compound containing a furan subcyclic group (4). Six new macrocyclic diester compounds (7‐12) could only be prepared using the base catalyzed transesterification process since the acid chloride synthetic method failed or the acid chloride could not be made. The formation of compounds 5 and 6 from dimethyl 2, 6‐pyridine dicarboxylate (17) and the triethylene and tetraethylene glycols proceded by way of half‐transesterified intermediates. These intermediates were also observed for the base catalyzed decomposition of 5 and 6 in methanol to form the glycol and the diester 17.

A color change from purple to green takes place on addition of tetrathiafulvalene (TTF) to the macrobicyclic receptor 1 , which is composed of a cyclobis(paraquat-p-phenylene) tetracation that shares one of its paraphenylene rings with a 1,5-naphthoparaphenylene-[36]crown-10 macrocycle. The TTF molecule forces the macrobicycle to turn inside out (see schematic drawing below) and displaces the self-complexed 1,5-dioxynaphthalene ring system from the center of the tetracationic cyclophane.