ChemInform Abstract: α- und β-Carboxylic Groups an Primary Ligating Groups in Promoting Amide Deprotonation. Solid-State Behavior of N-Tosylalaninate-Copper(II) Complexes: Crystal und Molecular Structures of Bis(N-tosyl-β-alaninato)bis(imidazole)copper(II

1985 ◽  
Vol 16 (29) ◽  
Author(s):  
L. ANTOLINI ◽  
L. P. BATTAGLIA ◽  
A. BONAMARTINI CORRADI ◽  
G. MARCOTRIGIANO ◽  
L. MENABUE ◽  
...  
2021 ◽  
Vol 76 (3-4) ◽  
pp. 193-199
Author(s):  
Muhammad Said ◽  
Sadia Rehman ◽  
Muhammad Ikram ◽  
Hizbullah Khan ◽  
Carola Schulzke

Abstract Three guanidine-derived tri-substituted ligands viz. N-pivaloyl-N′,N″-bis-(2-methoxyphenyl)guanidine (L1), N-pivaloyl-N′-(2-methoxyphenyl)-N″-phenylguanidine (L2) and N-pivaloyl-N′-(2-methoxyphenyl)-N″-(2-tolyl)guanidine (L3) were reacted with Cu(II) acetate to produce the corresponding complexes. The significance of the substituent on N″ for the resulting molecular structures and their packing in the solid state has been studied with respect to the structural specifics of the corresponding Cu(II) complexes. The key characteristic of the guanidine-based metal complexation with Cu(II) is the formation of an essentially square planar core with an N2O2 donor set. As an exception, in the complex of L1, the substituent’s methoxy moiety also interacts with the Cu(II) center to generate a square-pyramidal geometry. The hydroxyl groups of the imidic acid tautomeric forms of L1–L3, in addition to N″, are also bonded to Cu(II) in all three complexes rather than the nitrogen donor of the guanidine motif.


1997 ◽  
Vol 34 (8) ◽  
pp. 1395-1412
Author(s):  
G. David ◽  
J. M. Buisine ◽  
A. Daoudi ◽  
C. Kolinski ◽  
A. Stoleriu ◽  
...  

2016 ◽  
Vol 45 (9) ◽  
pp. 3974-3982 ◽  
Author(s):  
Riccardo Pettinari ◽  
Fabio Marchetti ◽  
Claudio Pettinari ◽  
Francesca Condello ◽  
Brian W. Skelton ◽  
...  

Mono- and tetranuclear Ru(ii) half-sandwich complexes containing acylpyrazolone ligands. 13C and 15N solid state NMR spectroscopy.


Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6731
Author(s):  
Haruki Inoue ◽  
Yuga Yamashita ◽  
Yoshiki Ozawa ◽  
Toshikazu Ono ◽  
Masaaki Abe

Two hexanuclear paddlewheel-like clusters appending six carboxylic-acid pendants have been isolated with the inclusion of polar solvent guests: [Cu6(Hmna)6]·7DMF (1·7DMF) and [Ag6(Hmna)6]·8DMSO (2·8DMSO), where H2mna = 2-mercaptonicotininc acid, DMF = N,N’-dimethylformamide, and DMSO = dimethyl sulfoxide. The solvated clusters, together with their fully desolvated forms 1 and 2, have been characterized by FTIR, UV–Vis diffuse reflectance spectroscopy, TG-DTA analysis, and DFT calculations. Crystal structures of two solvated clusters 1·7DMF and 2·8DMSO have been unambiguously determined by single-crystal X-ray diffraction analysis. Six carboxylic groups appended on the clusters trap solvent guests, DMF or DMSO, through H-bonds. As a result, alternately stacked lamellar architectures comprising of a paddlewheel cluster layer and H-bonded solvent layer are formed. Upon UV illumination (λex = 365 nm), the solvated hexasilver(I) cluster 2·8DMSO gives intense greenish-yellow photoluminescence in the solid state (λPL = 545 nm, ΦPL = 0.17 at 298 K), whereas the solvated hexacopper(I) cluster 1·7DMF displays PL in the near-IR region (λPL = 765 nm, ΦPL = 0.38 at 298 K). Upon complete desolvation, a substantial bleach in the PL intensity (ΦPL < 0.01) is observed. The desorption–sorption response was studied by the solid-state PL spectroscopy. Non-covalent interactions in the crystal including intermolecular H-bonds, CH···π interactions, and π···π stack were found to play decisive roles in the creation of the lamellar architectures, small-molecule trap-and-release behavior, and guest-induced luminescence enhancement.


Author(s):  
A.V. Yatsenko ◽  
K.A. Paseshnichenko ◽  
S.I. Popov

The crystal and molecular structures of 2-methyl-1-methylamino-anthraquinone (I) and 1-methylphenylamino-anthraquinone (II) were studied by the X-ray single-crystal diffraction and the visible spectra of crystalline specimens and their solutions were recorded. The molecule I is closely planar, whereas in the molecule II the amino group is 58° rotated out of the plane of the anthraquinone skeleton. In both structures the molecules pack in stacks. The comparison of experimental and calculated (on the DFT and AM1 levels) molecular structures, together with the comparison of experimental and INDO/S-calculated electronic spectra, give the evidence that molecular conformations (especially for II) change upon transfer from the solid state to solutions, and the π-delocalisation throughout the whole molecule enhances in the solid state.


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