Kinetic features of acid-base interaction of tetra(3-nitro-5-tert-butyl)phthalocyanine with nitrogen-containing bases in benzene

The kinetics of the reaction of acid-base interaction of tetra(3-nitro-5-tert-butyl)phthalocyanine with cyclic and acyclic nitrogen-containing bases in benzene was studied. The process is found to proceed with a low rate. The schemes of acid-base interaction are proposed and the probable structure of the proton transfer complexes of tetra(3-nitro-5-tert-butyl)phthalocyanine are discussed. The effect of the nature of the nitrogencontaining base on the kinetic parameters of the process is revealed.     

Kinetic stability of tetra(3-nitro-5-<Emphasis Type="Italic">tert</Emphasis>-butyl)phthalocyanine in the system nitrogen-containing base-DMSO

The state of tetra(3-nitro-5-tert-butyl)phthalocyanine in DMSO medium was studied. Sufficiently high stability of the obtained proton transfer complex is established, and its structure is suggested. It is shown that this complex is kinetically unstable in the highly basic media. Effect of the nature of cyclic and acyclic nitrogen-containing bases on the rate and activation parameters of destruction of the proton transfer complex of tetra(3-nitro-5-tert-butyl)phthalocyanine was found     

Kinetic characteristics of intermolecular proton transfer from NH groups of tetra(3-nitro-5-tert-butyl)phthalocyanine in nitrogen base-benzene systems

The kinetics of acid-base interaction between tetra(3-nitro-5-tert-butyl)phthalocyanine and cyclic and acyclic nitrogen bases in benzene was studied. The reaction was found to occur with a low rate. The structure and reactivity of protolytes were shown to be interrelated. The structure and stability of the proton-transfer complexes formed are considered.     

Kinetics of the Acid-Base Interaction between Tetra(4-<Emphasis Type="Italic">tert</Emphasis>-butyl)phthalocyanine and Nitrogen-Containing Bases in Dimethyl Sulfoxide

Specific features of the acid-base interaction of tetra(4-tert-butyl)phthalocyanine with cyclic and acyclic nitrogen-containing bases in dimethyl sulfoxide are studied. The effect of pK _a of proton-withdrawing molecules, basicity of a medium, and steric screening of acidic NH centers on the kinetic parameters of formation of proton-transfer complexes stable in time is shown.     

Synthesis and properties of tetra-(4-<Emphasis Type="Italic">tert</Emphasis>-butyl-5-nitro)phthalocyanines

The interaction of 4-tert-butyl-5-nitrophthalonitrile with a series of metal acetates has yielded the corresponding metal phthalocyaninates. The treatment of magnesium tetra(4-tert-butyl-5-nitro)phthalocyaninate with hydrochloric acid has afforded tetra(4-tert-butyl-5-nitro)phthalocyanine. Spectral properties of the prepared macrocycles have been studied. The nature of the organic solvent and the complex forming metal marginally affect the position of the Q band in the electron absorption spectra of the studied compounds. It has been demonstrated that the prepared phthalocyanines can dye polymer materials and are catalytically active towards oxidation of a model sulfur-containing compound.     

Creatinine sorbents based on nonwoven polymeric materials modified with tetra(4-tert-butyl)phthalocyanine and zinc complex

The experimental results, which show the possibility of immobilization of tetra(4-tert-butyl)phthalocyanine complex and its zinc complex on the surface of nonwoven polypropylene and lavsan materials. The alkali etching method was used for activation of the polypropylene surface. It was shown that the modified polymeric materials possess sorption activity relative to creatinine.     

Solvent effect on the photogeneration of singlet molecular oxygen by copper tetra(tert-butyl)phthalocyanine

The photogeneration of the singlet molecular oxygen (¹O₂) by copper tetra(4-tert-butyl) phthalocyanine in organic solvents of different nature was substantiated. The apparent quantum yields of ¹O₂in benzene and pyridine were determined. The data obtained indicate an influence of the coordinating properties of the solvent on the ¹O₂yield. However, this factor is not “critical” as in the case of photogeneration of ¹O₂by copper tetra(5-tert-butylpyrazino)porphyrazine.     

Mechanism of the quenching of O2(1Δ g ) by erbium tetra(4-tert-butyl)phthalocyanine

The quenching of singlet molecular oxygen (¹O₂, ¹Δ _g ) by Er³⁺ tetra(4-tert-butyl)phthalocyanine in benzene was studied by the luminescence method. The quenching was demonstrated to be controlled by a physical-chemical mixed mechanism, with donor-acceptor interactions being the main contributor to the physical quenching of ¹O₂.     

Catalytic hydrophosphorylation of semicarbazones, thiosemicarbazones, carbonohydrazones, and oxalyldihydrazones

Reaction of diethyl phosphite with semicarbazones, thiosemicarbazones, carbonohydrazones, and oxalyldihydrazones of aliphatic and carbocyclic ketones catalyzed by [tetra(tert-butyl)phthalocyanine]aluminum chloride resulted in hydrophosphorylation of the C=N bonds of hydrazones under study.     

The kinetics of proton transfer from octaphenylsubstituted tetraazaporphyrin to organic bases in benzene

The acid-base interaction of octa(m-trifluoromethylphenyl)tetraazaporphin with pyridine, 2-methylpiridine, morpholine, benzylamine, piperidine, n-butylamine, diethylamine, tert-butylamine, and triethylamine in benzene was studied. It was found that intermolecular transfer of spatially screened NH-group protons from octa(m-trifluoromethylphenyl)tetraazaporphin to morpholine, benzylamine, piperidine, n-butylamine, and tert-butylamine is characterized by unusually low values of rate constants. The effect of the structure of octa(m-trifluoromethylphenyl)tetraazaporphin, octa(n-bromophenyl)tetraazaporphin, octa(n-bromophenyl)tetraazaporphin, and octa(n-nitrophenyl)tetraazaporphin, and the nature of a base on the kinetic parameters of acid-base equilibrium is shown. A structure for complexes with proton transfer of octaphenylsubstituted tetraazaporphirins is suggested. It is revealed that they are subject to decomposition over time with the formation of low molecular colorless products.     

Formation of phthalocyanines deprotonated forms and their interaction with Zn Ions in the system 1,8-diazabicyclo[5.4.0]undec-7-ene-acetonitrile at 298 K

The formation of deprotonated forms of tetra(t-butyl)phthalocyanine ((H₂ tButPc) and octa(pentoxy)-phthalocyanine (H₂OAmPc) in the system acetonitrile-1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) at 298 K was studied by the method of spectrophotometric titration. With increasing DBU concentration sequential formation occurs of both mono- and douby deprotonated forms. The introduction of pentoxy groups into the fused benzene rings leads to a significant decrease in the acidity of the tetrapyrrole macrocycle compared with the tert-butyl substitution. The interaction of douby deprotonated forms of the phthalocyanines with zinc diacetate leads to the formation of metal complexes, the chelation constant of the latter is shown to correlate with the acidity of NH-protons in the nucleus of the macrocycle. For the chelation of more acidic tetra(t-butyl)-phthalocyanine an equimolar concentrations of zinc diacetate is sufficient, while the less acidic octa(pentoxy)-phthalocyanine requires almost 6-fold excess.     

Synthesis oftert-butyl substituted polymethine 1-benzothiopyrylium dyestuffs

A series of polymethine thiopyrylium dyestuffs of symmetrical and unsymmetrical structure, containing one to fourtert-butyl groups, has been synthesized from 6-tert-butyl-2-(p-tert-butylphenyl)-4-methyl-, 4,6-di(tert-butyl)-2-methyl-, and 6-tert-butyl-2,4-dimethyl-1-benzothiopyrylium perchlorates.     

Rational enhancement of the energy barrier of bis(tetrapyrrole) dysprosium SMMs via replacing atom of porphyrin core

With the coordination geometry of Dy^III being relatively fixed, oxygen and sulfur atoms were used to replace one porphyrin pyrrole nitrogen atom of sandwich complex [(Bu)₄N][Dy^III(Pc)(TBPP)] [Pc = dianion of phthalocyanine, TBPP = 5,10,15,20-tetrakis[(4-tert-butyl)phenyl]porphyrin]. The energy barrier of the compounds was enhanced three times, with the order of Dy^III(Pc)(STBPP) > Dy^III(Pc)(OTBPP) > [(Bu)₄N][Dy^III(Pc)(TBPP)] [STBPP = monoanion of 5,10,15,20-(4-tert-butyl)phenyl-21-thiaporphyrin, OTBPP = monoanion of 5,10,15,20-(4-tert-butyl)phenyl-21-oxaporphyrin]. Theoretical calculations offer reasonable explanations of such a significant enhancement. The energy barrier of 194 K for Dy^III(Pc)(STBPP) represents the highest one among all the bis(tetrapyrrole) dysprosium SMMs, providing a strategy to rationally enhance the anisotropy and energy barrier via atom replacement.     

Kinetic stability of substituted tetrapyrazinoporphyrazines in a system nitrogen base-dimethylsulfoxide

The state of tetra(5-tert-butylpyrazino)porphyrazine, octaethyltetrapyrazinoporphyrazine, octaphenyltetrapyrazinoporphyrazine in DMSO medium was studied. It was found that the complexes formed with the proton transfer exhibit a relatively high stability. In strong basic media these complexes are kinetically unstable. The influence of the nature of cyclic and acyclic nitrogen-containing bases, as well as the influence of NH-acidity of the porphyrazine macrocycle on the rate and activation parameters of decomposition of the proton-transfer complexes of tetra(5-tert-butylpyrazino)porphyrazine, octaethyltetrapyrazinoporphyrazine, and octaphenyltetrapyrazinoporphyrazine was established.     

The effects of substituents,molecular symmetry,ionic radius of the rare earth metal,and macrocycle on the electronic absorption spectra characteristics of sandwich-type bis(phthalocyaninato) and mixed (phthalocyaninato)(porphyrinato) rare earth complexes

The electronic absorption spectroscopic data for two series of 60 unsubstituted/substituted bis(phthalocyaninato) and mixed [tetrakis(4-chlorophenyl)porphyrinato](phthalocyaninato) rare earth complexes M(Pc)₂, M(Pc^∗)₂ and M(TClPP)(Pc) [M = Y, La…Lu except Pm; Pc^∗ = dianion of 2,3,9,10,16,17,23,24-octakis(4-methoxyphenoxy)phthalocyanine [Pc(MeOPhO)₈], dianion of 3(4),12(13),21(22),30(31)-tetra(tert-butyl)phthalocyanine (TBPc) and TClPP = tetra(4-chloro)phenylporphyrin] have been measured in CHCl₃. In this paper, the influence of the symmetry of macrocycle rare earth molecules, the effects of ionic radius of the rare earth metal and the influence of substituent species (tert-butyl and 4-methoxyphenoxy groups) onto the peripheral benzene rings on the electronic absorption characteristics of sandwich-type compounds have also been tentatively studied in detail.     

Study of thermal stability of tetraarenoporphyrazine metal complexes

Thermal stability in air of metal complexes of certain tetraarenoporphyrazines: tetrapyrazineporphyrazine, tetra-2,3-quinoxalinoporphyrazine, and tetra-2,3-naphtholocyanine, and also of copper complexes of tetra(tert-butyl)phthalocyanine, tetrapyrazineporphyrazine, and tetra-2,3-quinoxalinoporphyrazine substituted at the periphery was studied for the first time by the methods of thermogravimetry and differential thermal analysis. The effective thermal oxidation of these compounds occurs in the interval 620–820 K, and the tolerance for it is determined by both the metal nature and the structure of the macrocyclic ligand periphery.     

Synthesis and Properties of Tetra(4-<Emphasis Type="Italic">tert</Emphasis>-butyl-5-phenylsulfanyl)phthalocyanines and Their Derivatives

The methods of synthesis of 4-tert-butyl-5-sulfanylphenyl-and 4-tert-butyl-5-(4'-carboxyphenylsulfanyl) phthalonitriles have been developed and on their basis the corresponding octa-substituted phthalocyanines have been prepared. The effect of the structure of the above phthalocyanine derivatives on their electronic absorption spectra and parameters of thermal degradation in the presence of air oxygen were studied.     

Benzoylhydrazones in catalytic hydrophosphorylation

Reactions of benzoylhydrazones derived from heterocyclic and aromatic aldehydes and aliphatic, heterocyclic, and aliphatic-aromatic ketones with diethyl phosphite in the presence of [tetra(tert-butyl)phthalocyanine]aluminum chloride afford α-benzoylhydrazino phosphonates in high yields.     

Regioisomer-Free C4h β-Tetrakis(tert-butyl)metallo-phthalocyanines: Regioselective Synthesis and Spectral Investigations

Metal β-tetrakis(tert-butyl)phthalocyanines are the most commonly used phthalocyanines due to their high solubility, stability, and accessibility. They are commonly used as a mixture of four regioisomers, which arise due to the tert-butyl substituent on the β-position, and to the best of our knowledge, their regioselective synthesis has yet to be reported. Herein, the C_4h-selective synthesis of β-tetrakis(tert-butyl)metallophthalocyanines is disclosed. Using tetramerization of α-trialkylsilyl phthalonitriles with metal salts following acid-mediated desilylation, the desired metallophthalocyanines were obtained in good yields. Upon investigation of regioisomer-free zinc β-tetrakis(tert-butyl)phthalocyanine using spectroscopy, the C_4h single isomer described here was found to be distinct in the solid state to zinc β-tetrakis(tert-butyl)phthalocyanine obtained by a conventional method.     

Ligand exchange in the complexone-porphyrin macrocycle system in reactions of copper(II) ethylenediaminetetraacetate with porphyrins and phthalocyanines

Complexation between 5,10,15,20-tetraphenylporphine H₂TPP and tetra(tert-butyl)phthalocyanine H₂(t-Bu)₄Pc with copper(II) ethylenediaminetetraacetate in DMSO was studied by spectrophotometry. The kinetic parameters of the reaction were calculated and the mechanism of ligand exchange in the complexone-porphyrin macrocycle system was proposed. The reactivities of H₂TPP and H₂(t-Bu)₄Pc in reactions with copper ethylenediaminetetraacetate and some other copper chelate complexes were compared.