526 research outputs found
Tris(dipivalomethanato)holmium Induced NMR Shifts
Paramagnetic complexes of praseodymium and europium with 1,1,l,2,2,3,3- -heptafluoro-7, 7 ~dimethyl-4,6-octanedione [Pr(fod)3 and Eu(fod)3]1 and with 2,2,6,6-tetramethyl-3,5-heptanedione [Pr(DPM)3 and Eu(DPM)3] or sometimes ab:breviated as [Pr(tmhd)3 and Eu(tmhd)3]Z--5 have shown to !be very useful NMR shift reagents which can greatly s~mplify spectra of compounds having functional gro1ups with lone pair electrons. The only other lanthanide oormplex used for this :purpose was Yb(DPM)3 6>7 ā¢ However, Yb(DPM)3 exhibited a shift power between that of Pr(DPM)3 and Eu(DPM)3 and also strong line broadening8
and therefore did not offer any substantial advantage
To picture and to perform: The image of the Eucharistic Liturgy at Markov Manastir (I)
This paper presents and interprets the iconographic programme of the frescoes in the lowest register of the sanctuary in the church of St Demetrios at Markov Manastir in the context of the relationship between mural decoration and the contemporary Eucharistic rite. In the first part of the paper special attention is paid to the scene in the north pastophorion, which illustrates the prothesis rite, and the depiction of the Great Entrance, placed in the sanctuary apse. The iconographic and programmatic features of the fresco ensemble, the most pominent place among which is occupied by the representations of the deceased Saviour and Christ the Great Archpriest - are compared to various liturgical sources and visual analogies (monumetal painting and liturgical textiles) in the medieval art of Serbia and Byzantium. [Projekat Ministarstva nauke Republike Srbije, br. 177003: Medieval heritage of the Balkans: Institutions and culture
Artistic Trends on the Periphery ā the Lands of the BalÅ”iÄ, KosaÄa and CrnojeviÄ families
The man of sorrows and the lamenting virgin: The example at Markov Manastir
The frescoes of the Man of Sorrows and the lamenting Virgin in the church of Saint Demetrios at Markov Manastir (1376/77) are depicted in the western part of the naos, which is a departure from their usual location in the sanctuary. The paper, therefore, looks at the location of these frescoes in the context of the entire fresco program at Markov Manastir. What is distinct is a conceptual link between the frescoes in the sanctuary and the depiction of the Dead Christ and the Virgin on the western wall. The relationship between the Incarnation and the death of Christ is considered from a theological and liturgical standpoint. Related examples of icons whose iconographic and thematic solutions share the same conceptual tenets are also analyzed, as well as the influence of the texts read during the Passion Service on the placement of the frescoes of the Dead Christ and the Virgin. [Projekat Ministarstva nauke Republike Srbije, br. 177003: Medieval Heritage of the Balkans: Institutions and the Culture
Smiljka GabeliÄ, Äelopek. Church of St. Nicholas (14th and 19th century)
Smiljka GabeliÄ, Äelopek. Crkva Sv. Nikole (XIV i XIX vek
To picture and to perform: The image of the Eucharistic liturgy at Markov Manastir (II)
The themes in the sanctuary decoration at Markov Manastir (Christ Emmanuel, Virgin Orans, Descent of the Holy Spirit on the Apostles), whose peculiar iconographic elements reveal the mysteries of the Holy Trinity and the archpriesthood of Christ in the liturgical and theological context of the fourteenth century, are discussed in this paper. The remains of the text in the leitourgikon held by Christ the Archpriest have been re-examined. It seems plausible to assume that the inscription or a part of it referred to the opening dialogue of the anaphora. The iconographic peculiarities of individual items carried in the Great Entrance procession, modelled according to the structure of the archieratical Divine liturgy, have been reconsidered. It has been established that the way in which the large aer was carried, and its place in the procession escorting the Eucharistic gifts - which was very close to the holy offerings - followed the iconographic tradition of the Heavenly Liturgy in the dome, while the evidence for its shape and size can be found in a somewhat later liturgical source - the Patriarchal liturgical Diataxis of Dimitrios Gemistos. [Projekat Ministarstva nauke Republike Srbije, br. 177003: Medieval heritage of the Balkans: institutions and culture
Synthesis of the Four Structural Isomeric L-Pentapeptides of Ala. Glu. Lys. Ala. Ala. Sequence: Characterization and Correlation with the L-D-L-D-D-lsomer Related to the Peptidoglycan Peptide Chain
The synthesis of the four L-pentapeptides containing the Ala.
Glu. Lys. Ala. Ala. sequence, which differ with regard to the \u27sHe
of linkage between the glutamyl-lysyl residues, is described.
In each case the chain was built by coupHng the protected N-
termi:nal dipeptide N-hydroxysuccinimide esiter (II or IV) with
the C-terminal tripeptide benzyl ester (VIII or X). The sequentially
.identical L-D-L-D-D-pentapeptide having the y-carboxy-group
of D-glutamic acid residue involved in the .peptide Ā·bond, was prepared
after the same general pattern. Complete deprotection of the
isomers i111 two successive steps gave the free pentapeptides which
were characterized as solid di-trifluoroacetate salts by analytical,
optical and proton NMR spectral data. The isomers were compared
by paper electrophoresis at different pH values. The alantne methyl
resonances in the NMR spectra of the a-a L-pentapeptide XVIII
and the y-a L-D-L-D-D-pentapeptide XXII were assigned by observing
the shift in spectral lines with varying pH
Stacking interactions between chelate and phenyl rings in square-planar complexes of Cu, Ni, Pt and Pd
Previous analysis of geometrical parameters in the crystal structure of square-planar complexes, with and without chelate rings, of all transition metals from Cambridge Structural Database shows that there are stacking interactions between the phenyl ring and the chelate ring with delocalized -bonds. To investigate whether the type of metal atom influence this interaction we compare stacking parameters for the complexes with and without chelate rings in the complexes containing Cu(II), Ni(II), Pd(II) and Pt(II) metals. While the overall picture is similar for all four cases, complexes of Pd and Pt without chelate ring show tendency to form shorter contacts towards aromatic carbon. It was found that this behaviour is associated with the presence of cyano or isocyano derivatives as ligands.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200
Molecular and Crystal Structure of the Bis(Acetato)-Bis(4- Methyl-1h-Pyrazole)-Zinc(Ii)
Due to the low CO2 emission of geopolymers compared to Portland cement, interest in their use as binding cement has increased in recent years. The main goal of this research is to relate the green and sustainable characteristics to the good mechanical and chemical properties of fly ashbased geopolymers. For those purposes, samples of different ratios of fly ash (FA) and metakaolin (MK) were prepared. Mineralogical characterization of the geopolymer samples conducted using X-ray powder diffraction (XRD) showed that in the geopolymer synthesis reaction new amorphous phase was formed. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) confirmed characteristic bands of Si-O and O-Si-O groups at 1045 cmā1 . Compressive strength analysis revealed that the optimal ratio of FA and MK is 50:50 and exhibits the highest value, while X-ray photoelectron spectroscopy (XPS) analysis revealed the total reduction of carbon content in the alkali activated geopolymer with optimal stoichiometry 50:50. The results of this research indicates the possibility to obtain a geopolymer material with almost complete absence of carbon, which implies further application as a material with very high environmental potential and zero carbon emission.distorted tetrahedral environment. Different pattern of non-bonding interactions involving chemically equivalent ligands influence the overall shape of the complex molecule. This is evident in different mutual position of the pyrazolyl and acetato ligands, which is associated with different hydrogen bonds. Two neighboring complex molecules forms hydrogen bonded dimer. There are no significant intermolecular contacts between dimmer
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