The Synthesis and Complex Forming Capacity of Phosphorus-containing Macrocycles

Abstract

Corrosion-related defects in pure Al and AA 2037 Al alloy have been investigated by positron beam-based Doppler broadening energy spectroscopy. Defect profiles have been analyzed by measuring the S parameter as a function of incident positron energy up to 30 keV. When pure Al samples are immersed in 1M NaOH for various times, a significant increase in the S parameter near the surface is observed. This implies that the corrosion process involves the creation of defects and nanometer voids. In contrast, a significant decrease in the S parameter is observed after the corrosion of water-quenched Al alloy by the same method, which is interpreted as being a result of Cu enrichment near the metal-oxide interface layer.

A convenient synthesis of 2,7-dioxa-5,10-diaza-3λ5,8λ5-diphospha-1,6(1,4)-dibenzenacyclodecaphanes

“…Therefore, much attention is given to the development of methods of synthesis of such compounds [1][2][3][4][5][6][7].…”

“…Therefore, much attention is given to the development of methods of synthesis of such compounds [1][2][3][4][5][6][7].We previously showed for the first time [8] that p-(benzylideneamino)phenol in the absence of other bases reacts with dialkyl phosphorochloridites in chloroform to give phosphorus-containing [4.4]paracyclophane analogs. The present communication reports on the results of analogous reactions with substituted iminophenols both in the absence (Scheme 1) and in the presence of other base (Scheme 2).…”

Complexes of crown-containing N-thioacylamido(thio)phosphates with Zn(II) and Co(II) cations

“…Presence of the exocyclic functional groups in a molecule of crown-ether, interacting with atoms of a cycle or metal cations, increases complexing selectivity and complexing ability in relation to metal ions, and results in a change of the hydrophilic-hydrophobic balance and surface-active properties [8,9].…”

“…

Reaction of the potassium salts of N-acylamido(thio)phosphates [4 0 -benzo-15-crown-5]NHC(S)NHP(Y)(OiPr) 2 (Y = S, HL I ; Y = O, HL II ) with Zn(II) and Co(II) cations in aqueous EtOH leads to complexes of formulae Zn(L I,II À S,Y) 2 (Y = S, 1; Y = O, 2) and Co(L I -S,S 0 ) 2 (3), while interaction of the potassium salt of [4 0 -benzo-15-crown-5]C(S)NHP(O)(OiPr) 2 (HL III ) with Zn(II) in the same conditions leads to a complex of composition Zn(HL III )(L III -S,O) 2 (4).Compounds containing two essentially different complexing groups simultaneously -a chelating fragment and a macrocycle -draw the attention of researchers as potential bimetallic catalysts [1], models at studying intracomplex redox processes [2][3][4][5] and reagents for the synthesis of supramolecular compounds [6,7].Presence of the exocyclic functional groups in a molecule of crown-ether, interacting with atoms of a cycle or metal cations, increases complexing selectivity and complexing ability in relation to metal ions, and results in a change of the hydrophilic-hydrophobic balance and surface-active properties [8,9].Earlier, we had reported about bis-thioureas, containing diaza-18-crown-6 and diaza-15-crown-5 [10], thiourea on the basis of monoaza-18-crown-6 [11] and thiophosphorylated thiobenzamide [12], containing a benzo-15-crown-5 cycle, possessing the ability for complexes with alkaline and transition metal cations.Combination of crown-ether and thioacylamido(thio)-phosphate fragments C(S)NHP(Y) in one molecule opens greater opportunities for the synthesis of various supramolecular coordination compounds. Herein, we present complexes of Zn(II) and Co(II) cations (1-4) with ligands HL I-III (Scheme 1) [13].

…”

Aromatic λ3 heterocycles XIV. Fosfinine-ether macrocyclesheterocycles XIV. Fosfinine-ether macrocycles

“…Phosphinine ether macrocycles, the analogues of phosphine-ether macrocycles are designed as flexible and selective ligands in view to obtain host-guest complexes with metal cations [3]. Even if crown ethers and phosphine-ether macrocycles display interesting coordinative behavior towards metals or neutral molecules, due to optical isomerism of phosphorus atoms they posses many practical problems [5][6][7][8][9][10][11][12][13]. The aromatic character of phosphinine was demonstrated earlier by structural and magnetic criteria and also by spectral investigation [14][15][16][17][18].…”