Five subsequent new pyridine carboxamides and their complexes with d-electron ions. Synthesis, spectroscopic characterization and magnetic properties

Kwiatek, Dorota; Kubicki, Maciej; Skokowski, P.; Gruszczyńska, J.; Lis, Stefan; Hnatejko, Zbigniew

doi:10.1016/j.molstruc.2018.10.083

Cited by 5 publications

(8 citation statements)

References 55 publications

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“…Cl and Br turned out to be very strong ligands to Cu II compared with the amides and we avoided them in these experiments. Similar observations that Cu-halide bonding dominates the structures of heteroleptic halide pyridine-amide Cu II complexes were reported before [3,5,[25][26][27]38,40]. Using the same reaction protocol but varying the Cu:ligand ratio, 10 out of these 18 compounds could be reliably reproduced in good to excellent yields and high phase purity as confirmed through elemental analyses and powder XRD (Scheme 2).…”

Section: Synthesis Of the Cu Complexessupporting

confidence: 80%

“…In metalloenzymes, carboxylate side chains of the peptide are very frequent ligands and were preferably coordinated by hard metal ions, as expected. In contrast to this, carboxamide side chains were less preferred as ligands in metalloenzymes [34][35][36], in agreement with the observation that the carboxamide function coordinates only effectively in chelate ligands as 2-pyridine or 2-pyrazine carboxamides [1][2][3]5,6,[15][16][17][18][19][20][22][23][24][25][26]32,[37][38][39][40][41].…”

Section: Introductionsupporting

confidence: 65%

“…Higher values were due to spin-orbit coupling which is caused through heavy atoms such as Br or Cl. For our compounds only light N, O, or F atoms bind to Cu II [3,5,10,15,19,52,56]. sorption Spectroscopy in the Solid and in Solution ll microcrystalline materials show colours corresponding to absorptions in the visible reg absorption spectroscopy on selected samples (Table 5) reveals low-wavelengths absorpti g from 640 to 780 nm (15,600 to 12,820 cm −1 ) which were assigned to the typical Cu II d 9 syst rison of the three Pya-containing species reveals that the highest absorption energy ed for [Cu(Pya)2](BF4)2 ( 9) with a tetrahedrally elongated (OE) structure, followed a)2(H2O)(NO3)](NO3) (10) having an SPy+1 configuration with the sixth ligand marke ted, while [Cu(Pya)(NO3)2] (11) exhibits a maximum red-shifted by 2810 cm −1 in line with pyramidal (SPy) coordination.…”

Section: X-band Epr Spectroscopy and Magnetic Measurementsmentioning

confidence: 99%

“…One reason is their use as versatile building blocks in coordination polymers and MOFs for various applications [1][2][3]8,9,[11][12][13]16,20,21,26,27]. Another important reason is the biological relevance of some of the ligands used in this study (Scheme 1) [4][5][6]17,18,24,33]. An interesting general aspect of these ligands is the preference of Cu II to the different (offered) donor atoms in the ligands.…”

Section: Introductionmentioning

confidence: 99%

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CuII Complexes and Coordination Polymers with Pyridine or Pyrazine Amides and Amino Benzamides—Structures and EPR Patterns

et al. 2020

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Isonicotine amide, picoline amide, pyrazine 2-amide, 2- and 4-amino benzamides and various CuII salts were used to target CuII complexes of these ligands alongside with 1D and 2D coordination polymers. Under the criterion of obtaining crystalline and single phased materials a number of new compounds were reliably reproduced. Remarkably, for some of these compounds the ideal Cu:ligand ratio of the starting materials turned out to be very different from Cu:ligand ratio in the products. Crystal and molecular structures from single-crystal XRD were obtained for all new compounds; phase purity was checked using powder XRD. We observed exclusively the Oamide and not the NH2amide function binding to CuII. In most of the cases; this occurred in chelates with the second pyridine, pyrazine or aminophenyl N function. µ-O,N ditopic bridging was frequently observed for the N = pyridine, pyrazine or aminophenyl functions, but not exclusively. The geometry around CuII in these compounds was very often axially elongated octahedral or square pyramidal. X-band EPR spectra of powder samples revealed various spectral symmetry patterns ranging from axial over rhombic to inverse axial. Although the EPR spectra cannot be unequivocally correlated to the observed geometry of CuII in the solid state structures, the EPR patterns can help to support assumed structures as shown for the compound [Cu(Ina)2Br2] (Ina = isonicotine amide). As UV-vis absorption spectroscopy and magnetic measurement in the solid can also be roughly correlated to the surrounding of CuII, we suggest the combination of EPR, UV-vis spectroscopy and magnetic measurements to elucidate possible structures of CuII compounds with such ligands.

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Section: Synthesis Of the Cu Complexessupporting

confidence: 80%

Section: Introductionsupporting

confidence: 65%

Section: X-band Epr Spectroscopy and Magnetic Measurementsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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CuII Complexes and Coordination Polymers with Pyridine or Pyrazine Amides and Amino Benzamides—Structures and EPR Patterns

et al. 2020

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“…A Curie–Weiss fit of the inverse magnetic susceptibility yields nearly identical effective magnetic moments of µ eff = 1.98 µ B for CuL 1 and µ eff = 2.00 µ B for CuL 2 . Both are constant over a wide temperature range and within the range from 1.7 to 2.2 µ B experimentally observed for similar Cu(II) complexes at room temperature [ 25 , 64 , 65 , 66 , 67 , 68 , 69 , 70 ]. The effective moments being larger than the spin-only value of 1.73 µ B expected for a 3d 9 configuration ( S = 1/2) indicate spin-orbit coupling [ 23 , 37 , 39 , 64 , 65 ].…”

Section: Resultssupporting

confidence: 55%

Structure, Optical and Magnetic Properties of Two Isomeric 2-Bromomethylpyridine Cu(II) Complexes [Cu(C6H9NBr)2(NO3)2] with Very Different Binding Motives

et al. 2023

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Two isomeric 2-bromomethylpyridine Cu(II) complexes [Cu(C6H9NBr)2(NO3)2] with 2-bromo-5-methylpyridine (L1) and 2-bromo-4-methylpyridine (L2) were synthesized as air-stable blue materials in good yields. The crystal structures were different with [Cu(L1)2(NO3)2] (CuL1) crystallizing in the monoclinic space group P21/c, while the 4-methyl derivative CuL2 was solved and refined in triclinic P1¯. The orientation of the Br substituents in the molecular structure (anti (CuL1) vs. syn (CuL2) conformations) and the geometry around Cu(II) in an overall 4 + 2 distorted coordination was very different with two secondary (axially elongated) Cu–O bonds on each side of the CuN2O2 basal plane in CuL1 or both on one side in CuL2. The two Br substituents in CuL2 come quite close to the Cu(II) centers and to each other (Br⋯Br ~3.7 Å). Regardless of these differences, the thermal behavior (TG/DTA) of both materials is very similar with decomposition starting at around 160 °C and CuO as the final product. In contrast to this, FT-IR and Raman frequencies are markedly different for the two isomers and the UV–vis absorption spectra in solution show marked differences in the π–π* absorptions at 263 (CuL2) or 270 (CuL1) nm and in the ligand-to-metal charge transfer bands at around 320 nm which are pronounced for CuL1 with the higher symmetry at the Cu(II) center, but very weak for CuL2. The T-dependent susceptibility measurements also show very similar results (µeff = 1.98 µB for CuL1 and 2.00 µB for CuL2 and very small Curie–Weiss constants of about −1. The EPR spectra of both complexes show axial symmetry, very similar averaged g values of 2.123 and 2.125, respectively, and no hyper-fine splitting.

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Solvent effects on spectroscopic, electronic, and topological analyses, Hirshfeld surface, ADME, and molecular docking studies on antiviral pyridine carboxamide derivatives

Eşme,

Kwiatek,

Hnatejko

2024

Journal of Molecular Liquids

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Five subsequent new pyridine carboxamides and their complexes with d-electron ions. Synthesis, spectroscopic characterization and magnetic properties

Cited by 5 publications

References 55 publications

CuII Complexes and Coordination Polymers with Pyridine or Pyrazine Amides and Amino Benzamides—Structures and EPR Patterns

CuII Complexes and Coordination Polymers with Pyridine or Pyrazine Amides and Amino Benzamides—Structures and EPR Patterns

Structure, Optical and Magnetic Properties of Two Isomeric 2-Bromomethylpyridine Cu(II) Complexes [Cu(C6H9NBr)2(NO3)2] with Very Different Binding Motives

Solvent effects on spectroscopic, electronic, and topological analyses, Hirshfeld surface, ADME, and molecular docking studies on antiviral pyridine carboxamide derivatives

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