Coordination Chemistry in Non-Aqueous Solutions

Gutmann, V.

doi:10.1007/978-3-7091-8194-2

Cited by 407 publications

(97 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…24 The formation of mono-zincpyridinates on porphyrins moieties is very well documented. In solution, zincporphyrins will exist as a five coordinate square pyramidal species, with only one face available for heterodimer formation.…”

Section: Zn(ii)porphyrins/mpcts Systems (M =Cu Ni)mentioning

confidence: 99%

Synthesis of new cationic metalloporphyrins and heterodimer formation with anionic metallophthalocyanines

Ribeiro

Azzellini

2003

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

Existe grande interesse no estudo de heterodímeros constituídos por metaloporfirinas e ftalocianinas de carga oposta, uma vez que estes sistemas são modelos do special pair da fotossíntese e dispositivos moleculares promissores para a transferência de elétrons unidirecional. Neste trabalho foram sintetizadas novas metaloporfirinas catiônicas, e investigada a formação de heteroagregados com metaloftalocianinas aniônicas em DMSO. Estes novos derivados porfirínicos catiônicos apresentam grupos benzílicos ligados aos nitrogênios piridínicos da tetra-(piridil)porfirina (H 2 TPyP), resultando em compostos que são mais hidrofóbicos e que apresentam sistemas π adicionais em relação aos ligantes tetra-(metilpiridínio)porfirina (H 2 TMPyP) e tetra-(trimetilaminofenil)porfirina (H 2 TAPP). Observou-se que a estequiometria dos agregados formados e os valores de constante de associação entre as porfirinas catiônicas e as ftalocianinas aniônicas são dependentes do metal coordenado a ambos os macrociclos. As Zn(II)porfirinas formam em solução preferencialmente o agregado de estequiometria 1:1 (porfirina:ftalocianina) no meio reacional, enquanto que no caso das Pd(II)porfirinas pode ocorrer a formação de agregados 1:1 ou 1:2 (porfirina:ftalocianina). Os valores de K PI , por sua vez, são sempre maiores para os agregados formados com as ftalocianinas de Cu(II), sendo este comportamento relacionado com a menor distorção para fora do plano da ligação Cu-N comparada com a ligação Ni-N em decorrência da ligação axial de uma molécula de DMSO ao íon metálico coordenado à ftalocianina. Os valores de K PI também são menores para os heterodímeros formados com as porfirinas que apresentam os meso-susbtituintes benzílicos mais volumosos, em função da disposição angular dos mesmos em relação ao plano do anel porfirínico que provoca um maior impedimento estérico. Estes resultados demonstram que a associação entre macrociclos tetrapirrólicos pode ser controlada através de vários fatores estruturais. Estes fatores também podem conduzir a diferentes propriedades fotofísicas destes heteroagregados; estudos neste sentido estão em andamento.There is great interest in the investigation of heterodimers formed by metalloporphyrins and metallophthalocyanines grafted with oppositely charged substituents, since these systems are models of the photosynthetic special pair and promising unidirectional electron transfer molecular devices. In the present study new cationic metalloporphyrin derivatives were synthesized and their association with anionic metallophthalocyanines forming heteroaggregates, investigated. These new cationic porphyrins derivatives show benzylic groups bound to the pyridyl nitrogen atoms of tetra-(pyridyl)porphyrin (TPyP), resulting in additional π systems and more hydrophobic compounds if compared with tetra-(methylpiridinium)porphyrin (H 2 TMPyP) and tetra-(trimethylaminophenyl)porphyrin (H 2 TAPP) ligands. It could be observed that both stoichiometry and association constants between cationic porphyrins and anionic phthalocyanines ...

show abstract

Section: Zn(ii)porphyrins/mpcts Systems (M =Cu Ni)mentioning

confidence: 99%

Synthesis of new cationic metalloporphyrins and heterodimer formation with anionic metallophthalocyanines

Ribeiro

Azzellini

2003

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…The empirical parameters of the solvent polarity were used as basic data sets. These parameters can be obtained directly from literature [32]. The extraction of the chemical information contained in such a data set can be carried out by statistical method of Multiple Linear Regression analysis (MLR).…”

Section: Experimentlmentioning

confidence: 99%

Solvatochromism Study on the Copper(II) Complexes Containing 3–Substituted Derivatives of Acetylacetonate Ligands

Golchoubian¹

2012

IJEE

View full text Add to dashboard Cite

show abstract

“…46,47 Data preprocessing and data analysis were carried out in MATLAB software (Version 7.5, MathWorks, Inc.) environment, and the deconvolution of the obtained data matrix was performed using the software's SQUAD, DATAN and SPECFIT/32. All calculations were run on a TOSHIBA laptop computer with Pentium (IV) as central processing unit with Windows XP as operating system.…”

Section: Apparatus and Softwaresmentioning

confidence: 99%

Spectrophotometric Study of Acidity and Complex Formation of Anti-Inflammatory Drug Piroxicam with Some Transition Metal Ions in Different Methanol/Water Mixtures by Chemometric Methods

Ghasemi¹,

Jalalvand²

2009

Journal of the Korean Chemical Society

View full text Add to dashboard Cite

ABSTRACT. The complex formation of anti-inflamatory drug piroxicam (PX, 4-hydroxy-2-methyl-N-2--pridyl-2H-1,2-benzothiazine-3-carboxadiamide-1,1-dioxide) with transition metal ions Co(II), Ni(II), Cu(II) and Zn(II) in methanol(MeOH)/water binary mixtures were studied by spectrophotometric method at 25 o C, constant pH = 5.0 and I = 0.1 M. The computer program SQUAD was used to extract the desired information from the spectral data. The outputs of the fitting processes were stability constants, standard deviations of the estimated stability constants, concentration distribution diagrams and spectral profiles of all species. The sequence of the stability constants of PX complexes with Co(II), Ni(II), Cu(II) and Zn(II) follow the Cu(II) > Co(II) > Ni(II) ≈ Zn(II) order. This may be due to different geometry tendencies of these metal ions. The acidity constants of the PX were also determined under above condition from its absorption spectra at different pH values. The computer program DATAN was used for determination of acidity constants of PX. The validity of the obtained acidity constants was checked by a well known computer program SPECFIT/32. The effects of the different parameters like solvent nature, cations characteristics on the stability and acidity constants were thoroughly discussed.

show abstract

Coordination Chemistry in Non-Aqueous Solutions

Cited by 407 publications

References 0 publications

Synthesis of new cationic metalloporphyrins and heterodimer formation with anionic metallophthalocyanines

Synthesis of new cationic metalloporphyrins and heterodimer formation with anionic metallophthalocyanines

Solvatochromism Study on the Copper(II) Complexes Containing 3–Substituted Derivatives of Acetylacetonate Ligands

Spectrophotometric Study of Acidity and Complex Formation of Anti-Inflammatory Drug Piroxicam with Some Transition Metal Ions in Different Methanol/Water Mixtures by Chemometric Methods

Contact Info

Product

Resources

About