Tautomerism of Diisopropoxyphosphoryl Benzylisothiourea

Abstract

As part of our studies in preparation and physical properties of Potential ligands containing l-phosphoryl(P?O)-3-3-carbonyI(C?X, X?NH, O or S) group, we have investigated the intrdinta molecular hydrogen bonding of diisoproxy- phosphorylquanidine[l] as well as the tautomerism of phosphoryl benzylisothiourea. These are of interest as in interpretation of their chelation behavior as well as in development of other potential ligands for specific metal cations.     

Mixed-ligand complex formation of (2,2′,2″-terpyridine)copper(I) and (2,2′2″-terpyridine)copper(II) with some sulfur-containing amino acids

Summary Mixed-ligand complex formation of copper(I) with 2,2,2-terpyridine (terpy) and various biologically significant sulfurcontaining amino acids, L [L = cysteine, penicillamine,N-acetylcysteine andN-acetylpenicillamine] was investigated. WithN-acetylcysteine andN-acetylpenicillamine, copper(I) complexes [Cu(terpy)L]HCl have been isolated and characterised. The amino acid in each case bonds to the copper(I) through the sulfur atom only. These complexes are readily oxidised to the corresponding copper(II) complexes which contain a Cu^II-S(mercaptide) bond as demonstrated by the (S)Cu^II LMCT at 420 nm. The e.p.r. and electronic spectroscopic results are consistent with a distorted octahedral structure. Reactions of copper(I) with terpy and cysteine/ penicillamine in weakly acidic medium produce complexes containing two different copper(II) centres. From a strongly acidic medium, a binary copper(I) terpyridine complex is obtained instead and is shown from i.r. spectral absorptions to contain a protonated pyridyl ring.     

8,9-Methylenedioxy-3,4-dihydro-1,4,5-benzotriazocin-2(1H)-ones

The title compounds are obtained directly on reaction of 6-chloroacetamidopiperonal with substituted phenylhydrazines. Piperonal was used as starting material.     

Short chain acyclic crown ethers

A series of short chain acyclic crown ethers such as (1,2), (1,3), (1,4)-phenylenediethers and some symmetric or assymmetrico-substituted phenyl ethers were prepared. The complexation studies of these compounds were carried out by a) direct UV titration method, b) picrate extraction method and c) isolation of crystalline complex.Taken in part from the master's thesis ofMaria Cecilia Bastos Vieira de Souza, Instituto Militar de Engenharia, 1978.     

New multidentate potential ionophors of ether-amide type

The syntheses of acyclic compounds featuring ether-amide groups and different terminal substituents are presented. Three series of new multidentate potential ligands were obtained.

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Neue mehrzähnige potentielle Ionophore des Ether-Amid-Typs

Zusammenfassung Es wird die Synthese acyclischer Verbindungen mit Ether-Amid-Gruppen und verschiedenen endständigen Substituenten beschrieben. Es wurden drei Verbindungsreihen erhalten, die neue potentielle mehrzähnige Liganden repräsentieren.

     

Mixed-ligand complex-formation of (2,2′,2″-terpyridine) copper(II) with monosubstituted phenolates

Summary The copper(II)-phenolate oxygen interaction in several mixed-ligand complexes of copper(II) containing a 2,2,2-terpyridyl and a phenolate has been studied by i.r., electronic, e.p.r. spectroscopies and conductometric and polarographic measurements. Electronic spectral results demonstrate the dependence of such interaction on the nature of the phenol as well as the solvent. Partial dissociation of the phenolate from the complex was detected in methanol at low concentrations (1×10^–4 M). In dimethyl sulphoxide the complexes remain intact. The X-band e.p.r. spectral data obtained at ambient temperature and at 77 K are consistent with the results from the electronic spectral and conductometric study.     

An ESR Study on Singlet Oxygen Photoproduction of the Meso-Tetrakis-(Substituted Phenyl) Porphine Derivatives

The ability of meso-tetrakis- (substituted phenyl) porphine derivatives for photo-generating singlet oxygen (O2) is studied by ESR spectrometry. The results show that the singlet oxygen yields of most of porphine derivatives are higher than that of HPD. It is also exhibited that the nature and structure of the substituent at the meso position are closely related to the photo-sensitizing ability of meso-tetrakis-(substituted phenyl) porphine.     

Phenylenedioxydiacetamide—End group effect

A series of neutral ligands featuring ether and amide groups were prepared. The complexation studies suggest a strong participation of the extra terminal amide group.Taken in part from the Master's Thesis of Antonio Paulo Altoé, Instituto Militar de Engenharia, Rio de Janeiro, Brasil (1979).