Self-assembly of novel macrocyclic aminomethylphosphines with hydrophobic intramolecular cavities

Abstract

Novel macroheterocyclic tetraphosphines, namely, 1,1',5,5'-bis(arylene)-bis(1,5-diaza-3,7-diphosphacyclooctanes) 2-6, were obtained without the use of high-dilution techniques or any matrix by the reaction of bis(hydroxymethyl)organylphosphines with primary aromatic diamines containing two p-phenylene fragments linked by various one-atom bridges in a molecular self-assembly process. The structures of 4, 5 and 6 were investigated by X-ray crystal structure analyses. The macrocyclic cavities can be described as a truncated rhombohedral prism with side faces formed by phenylene rings and 1,5-diaza-3,7-diphosphacyclooctanes in the truncated acute angles. In the crystals of these macrocycles, solvating DMF molecules are present, and a methyl group from each of two DMF molecules penetrates the macrocyclic cavities of 4 and 5 from either side, whereas only one disordered molecule of DMF penetrates the cavity of macrocycle 6. Different types of crystal packing are observed for the P-benzyl-substituted compounds 4 and 5 and for the P-mesityl-substituted compound 6: for 4 and 5 the formation of alternating layers containing the macrocycles and the DMF molecules is observed, in which the cavities of the macrocyclic molecules form channels and the DMF molecules are located in the centers of the channels; in the crystal of 6, six molecules are arranged around the 3 axis in the fashion of a six-bladed propeller.

New P,N-Containing Cyclophanes with Exocyclic Pyridyl Containing Substituents on Phosphorus Atoms

“…[25] The data obtained indicate that the structures of cyclophanes 1 and 2 are similar to that of previously described 28-membered cage P,N-containing macrocycles with two diazadiphosphacyclooctane fragments in chairchair conformations with axial lone electron pairs of phosphorus atoms directed inward the macrocyclic cavity. [18,21,25] The treatment of 1 and 2 with the excess of aqueous hydrochloric acid in chloroform leads to the formation of the microcrystalline precipitates of their monohydrochlorides 3 and 4 (Scheme 1) according to the elemental analysis data. …”

“…It should be mentioned that the oxidation of analogous P-aryl and P-benzyl substituted 28-membered macrocyclic tetraphosphines was often observed earlier under the conditions of the registration of MALDI mass-spectra. [25] Indeed 31 P NMR spectra of 1 and 2 show only one narrow signal of each macrocyclic phosphine at d P -55.3 ppm (1, CDCl 3 ) and -52.82 ppm (2, DMSO-d 6 ) that gives the evidence of the symmetrical structure of the macrocycles. The values of the chemical shifts indicate that the cyclophanes contain 1,5-diaza-3,7-diphosphacyclooctane fragments.…”

“…MALDI mass-spectrum of 5 shows the peaks of the monoxide of the corresponding 3,5,9,11-tetraoxa-1, The analogous oxidation of P,N-containing cyclophanes during the registration of MALDI mass-spectra was earlier observed for the macrocycles of various sizes. [19,25] NMR-spectra of both macrocycles 5 and 6 give the evidence of their symmetrical structures. Their signals in 31 P NMR spectra in DMSO-d 6 are narrow singlets at d P -45.59 ppm (5) and -56.35 (6).…”

“…The precipitate formed was filtered off at -10 --20 °C, washed with cold DMF and twice with acetonitrile and dried at 0.05 torr for 4 h. Yield: 0.090 g (7 % steps like previously described analogous macrocyclizations on the basis of primary aryl-and benzylphosphines. [18,24,25] At the first step (pyridine-2-yl)-or [2-(pyridine-2-yl) ethyl]phosphine have reacted with solid paraformaldehyde at elevated temperature (90-110 °C) to give corresponding bis(hydroxymethyl)organylphoshine. [10] On the second step the obtained diol has interacted with primary aromatic diamine in DMF at 100-110 °C.…”

Synthesis of novel paracyclophanes with linear P,N-containing spacers

“…The approach involves condensation of bis(hydroxymethyl)or ganylphosphines with primary diamines containing spac ers formed by two p phenylene fragments linked by vari ous monoatomic bridges. 17, 18 At high concentrations of the reagents and in the absence of templates, those reac tions mainly yielded macrocycles via covalent self as sembly. 18 The goal of the present work was to further develop this approach and use it for the synthesis of more flexible cyclophanes with two tricoordinate P atoms in the macrocycle.…”