The odd-even effect in luminescent [Eu (L) (H O) ]⋅y(H O) complexes with aliphatic dicarboxylate ligands (L: OXA, MAL, SUC, GLU, ADP, PIM, SUB, AZL, SEB, UND, and DOD, where x=2-6 and y=0-4), prepared by the precipitation method, was observed for the first time in lanthanide compounds. The final dehydration temperatures of the Eu complexes show a zigzag pattern as a function of the carbon chain length of the dicarboxylate ligands, leading to the so-called odd-even effect. The FTIR data confirm the ligand-metal coordination via the mixed mode of bridge-chelate coordination, except for the Eu -oxalate complex. XRD results indicate that the highly crystalline materials belong to the monoclinic system. The odd-even effect on the 4 f-4 f luminescence intensity parameters (Ω and Ω ) is explained by using an extension of the dynamic coupling mechanism, herein named the ghost-atom model. In this method, the long-range polarizabilities ( ) were simulated by a ghost atom located at the middle of each ligand chain. The values of were estimated using the localized molecular orbital approach. The emission intrinsic quantum yield ( ) of the Eu complexes also presented an the odd-even effect, successfully explained in terms of the zigzag behavior shown by the Ω and Ω intensity parameters. Luminescence quenching due to water molecules in the first coordination sphere is also discussed and rationalized.
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http://dx.doi.org/10.1002/cphc.201900603 | DOI Listing |
J Pharm Sci
January 2025
Development Sciences, Research and Development, AbbVie Inc., North Chicago, IL, 60064, United States; ProPhysPharm LLC, Lincolnshire, IL 60069, United States; Department of Industrial and Molecular Pharmaceutics, Purdue University, West Lafayette, IN 47907, United States. Electronic address:
The rapid and efficient cocrystal screening, based on solution-mediated phase transformation (SMPT), was applied to the screening of cocrystals between ketoconazole (KTZ) and nine aliphatic dicarboxylic acids. Cocrystals formed successfully, in minutes, with a change of suspension characteristics, either a cake formation or the formation of large particles. Bulk cocrystals were characterized by powder X-ray diffraction, thermal analysis, and Raman spectroscopy.
View Article and Find Full Text PDFAmino Acids
August 2024
Department of Biochemistry, Faculty of Science, Palacký University, Olomouc, Czech Republic.
Aldehyde dehydrogenases (ALDHs) represent a superfamily of enzymes, which oxidize aldehydes to the corresponding acids. Certain families, namely ALDH9 and ALDH10, are best active with ω-aminoaldehydes arising from the metabolism of polyamines such as 3-aminopropionaldehyde and 4-aminobutyraldehyde. Plant ALDH10s show broad specificity and accept many different aldehydes (aliphatic, aromatic and heterocyclic) as substrates.
View Article and Find Full Text PDFChem Asian J
November 2024
School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
Soft Matter
August 2024
Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland.
In this study, porous networks were efficiently prepared by crosslinking hydrophilic poly(2-isopropenyl-2-oxazoline) (PiPOx) with dicarboxylic polyesters (HOOC-PLA-COOH or HOOC-PCL-COOH) in the presence of sodium chloride as a water-soluble porogen. Importantly, by using a relatively simple synthetic protocol, the resulting spongy materials were freely formed to the desired size and shape while maintaining stable dimensions. According to the SEM data, the porous 3D structure can be altered by the pore dimensions, which are dependent on the porogen crystal size.
View Article and Find Full Text PDFChemistry
September 2024
Warsaw University of Technology, Faculty of Chemistry, Noakowskiego 3, 00-664, Warsaw, Poland.
Alumoxanes are typically produced via controlled hydrolysis of short-chain alkyl aluminium compounds which leads to oligomeric species that are usually difficult to obtain in crystalline form. Simultaneously, various alternative non-hydrolytic approaches to alumoxanes have also been used. In this work, we report on a new methylalumoxane scaffold derived from the alkylation of a series of dicarboxylic acids: itaconic acid (HOCCHC(=CH)COH), succinic acid (HOCCHCHCOH) and homophthalic acid (HOCCHCHCOH).
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