Structure determination, spectroscopic characterization, and magnetic properties of a novel dinuclear copper(II) crown ether bipyridine complex

Martens, Constantinus F.; Schenning, Albertus P. H. J.; Feiters, Martinus C.; Heck, Jürgen; Beurskens, Gezina; Beurskens, Paul T.; Steinwender, E.; Nolte, Roeland J. M.

doi:10.1021/ic00066a012

Cited by 28 publications

(13 citation statements)

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“…The shifting of this band could be correlated to the chaotropic character of BMIM + ions, diffused into the matrix, according to the literature [26]. This is consistent with the presence in the FTIR spectra of the shrunk gels, of small absorption bands at 3593 and 3531 cm -1 , characteristic for OH free groups [27]. In addition, the characteristic band for [BF 4 ]…”

Section: Ftir Spectra Of Pva/bmimbf 4 Gelssupporting

confidence: 85%

“…-from 1060 cm -1 [27] is split into three peaks and shifted to 1048, 1034 and 1017 cm -1 showing the lowering of B-F vibration symmetry, due to the F atom involving within H bonds with water molecules. Also the skeletal and C-O stretching band from 830 cm -1 from the PVA FTIR spectrum is shifted in the PVA/IL gels spectra to 844 and respectively 848 cm -1 , showing a stiffening of the polymeric chain as a consequence of the interaction by H bondings between OH groups of PVA.…”

Section: Ftir Spectra Of Pva/bmimbf 4 Gelsmentioning

confidence: 98%

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Study of the PVA hydrogel behaviour in 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid

Paţachia¹,

Friedrich²,

Florea³

et al. 2011

Express Polym. Lett.

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Abstract. The present paper aims at studying the behaviour of the poly(vinyl alcohol) [PVA] cryogel in the presence of 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM] + [BF 4 ] -) aqueous solutions with various concentrations. The gravimetric method showed that the swollen PVA cryogels exhibit mechanically active behaviour. PVA cryogels showed shrinking in the presence of ionic liquid, (IL), and re-swelling in the presence of distilled water. The re-swelling is not completely reversible, due to the influence of the IL ions on the gel morphology. The Fourier transform infrared (FTIR) spectra have indicated no chemical interaction between the PVA and the studied IL, but highlighted the gel crystallinity change as a function of IL concentration, as well as changes in the bound water amount. Rheological analyses showed dominating plastifying effect of the cation at a lower IL concentration and dominating kosmotropic effect of the anion at a higher IL concentration. A phenomenological kinetic equation that takes into account both fluxes of matters, in and out of the gel, is proposed, explaining the alteration of the gel properties when it comes in contact with BMIMBF 4 solutions.

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Section: Ftir Spectra Of Pva/bmimbf 4 Gelssupporting

confidence: 85%

Section: Ftir Spectra Of Pva/bmimbf 4 Gelsmentioning

confidence: 98%

Study of the PVA hydrogel behaviour in 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid

Paţachia¹,

Friedrich²,

Florea³

et al. 2011

Express Polym. Lett.

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“…Materials and reagents : Dichloro(1,5‐cyclooctadiene)platinum( II ), potassium tetrachloroplatinate( II ), and 2,2′:6′,2″‐terpyridine were obtained from Strem Chemicals Inc. 2,6‐Diphenylpyridine was obtained from Lancaster Synthesis Ltd. Ph 2 PB15C5,15 Ph 2 PDMP,15 pyCOA15C5,16 pyCON(CH 2 CH 2 OCH 3 ) 2 ,16 pyCCB15C5,17 and pyCCDMP17 were synthesized according to modifications of the methods described in the literature. [Pt(trpy)(MeCN)](OTf) 2 2b and [Pt(C^N^C)(dmso)]10b were synthesized according to the published procedures.…”

Section: Methodsmentioning

confidence: 99%

Syntheses, Electronic Absorption, Emission, and Ion-Binding Studies of Platinum(II) C^N^C and Terpyridyl Complexes Containing Crown Ether Pendants

et al. 2002

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A series of platinum (II) C^N^C complexes, [Pt(C^N^C) (L)] (HC^N^CH=2,6‐diphenylpyridine (dppy); L=Ph2PB15C5 (1, B15C5=benzo[15]crown‐5), Ph2PDMP (2, DMP=3,4‐dimethoxyphenyl), pyCOA15C5 (3, A15C5=aza[15]crown‐5), pyCON(CH2CH2OCH3)2 (4), pyCCB15C5 (5), pyCCDMP (6)) and terpyridyl complexes, [Pt(trpy)(L)](X)2 (trpy=2,2′:6′,2″‐terpyridine; L=Ph2PB15C5, X=OTf (7 a), PF6 (7 b); X=PF6, L=Ph2PDMP (8), pyCCB15C5 (9), and pyCCDMP (10)) have been successfully synthesized and characterized. The structures of 1, 3, and 7 a have been determined by X‐ray crystallography. Excitation of complexes 1–6 in EtOH/MeOH (4:1 v/v) glass gave high‐energy structured emission bands, assigned as derived from states of metal‐perturbed intraligand (IL) origin. At higher concentrations, complexes 3–6 each displayed an additional, structureless emission band at 600–615 nm, with complexes 5 and 6 showing an obvious increase in the intensity of this emission band when the concentration was increased further. In dichloromethane at room temperature, complexes 3–6 showed, in addition to the high‐energy emission at 490–505 nm, an extra, broad emission band at 620–625 nm when the concentration was increased. The emission origins of the low‐energy band in glass and in fluid solutions are suggested to be derived from the ground‐state oligomerization or aggregation process of the complexes. In the solid state at room temperature, complexes 1–6 each showed a broad, unstructured emission band at 560–600 nm, which was shifted to lower energy upon cooling to 77 K. On the other hand, the terpyridyl analogues 7–10 displayed intense vibronic‐structured intraligand (IL) emissions at 460–472 nm in butyronitrile glass at 77 K. Solid‐state samples of 9 and 10 displayed strong phosphorescence upon photoexcitation at 298 K and 77 K, tentatively assigned as derived from states of Pt(dπ)→π*(trpy) 3MLCT origin(MLCT=metal‐to‐ligand charge transfer). The ion‐binding properties of complexes 5 and 9 for Na+, Ba2+, and K+ ions have been studied by UV/Vis spectrophotometric methods, and confirmed by ESI mass spectrometric studies. The ion‐binding properties for Na+ ions have also been probed by 1H NMR experiments. For the same crown ether‐containing ligand and the same metal ions, the neutral cyclometalated complexes gave larger binding constants than the positively charged terpyridyl analogues.

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“…Selected Bond Distances [ä] and Angles [8] for [ Cu( L ) 2 ]PF 6 1a (L L 1 ), and 1b (L L 2 ) 1a Cu(1)ÀN (1) 2.028 (7) Cu(1)ÀN(4) 2.021(8) Cu(1)ÀN (3) 2.035 (7) Cu(1)ÀN (6) 1.998(7) N(1)ÀN (2) 1.35(1) N(4)ÀN (5) 1.38(1) N(1)ÀC (5) 1.34(1) N(5)ÀC(33) 1. 33(1) C(5)ÀC (4) 1.42(2) C(33)ÀC(32)…”

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confidence: 99%

Copper Complexes with New Pyridylpyrazole Based Ligands

Campo

Cano

Heras

et al. 2002

HCA

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We report the synthesis, characterization, and crystal structures of new ligands of the pyridinylpyrazole type, i.e., 3,5-bis(4-butoxyphenyl)-1-(pyridin-2-yl)-1H-pyrazole (L 1 ) and 3,5-bis(4-phenoxyphenyl)-1-(pyridin-2-yl)-1H-pyrazole (L 2 ) (Scheme 1), and the study of their coordination behavior towards Cu I and Cu II . The versatility of this type of ligand, which can give access to different coordination spheres about the metal center, depending on the nature of the copper starting material used in the preparation of the complexes (Scheme 2), is illustrated. Thus, pseudo-tetrahedral Cu I as well as six-coordinated tetragonal and distorted tetragonal pyramidal Cu II derivatives were obtained for [Cu(L) 2 ]PF 6 , [Cu(Cl) 2 (L) 2 ] (L L 1 , L 2 ), and [Cu(Cl)(L 1 ) 2 ]PF 6 , respectively. We also present a crystallographic support of a distorted octahedral cis-bis(tetrafluoroboratokF)copper(II) compound found for [Cu(BF 4 ) 2 (L 1 ) 2 ] (3).Introduction. ± Chelating ligands based on the pyrazole ring have been developed extensively in the last years [1] [2]. Most of the actual work deals with pyrazole rings bearing one or two bulky N-heterocycle substituents at the 3 and/or 5 position, as this type of ligand often produces multimetallic compounds [1 ± 6]. By constrast, related 1-substituted pyrazoles with heterocyclic substituents, which can act as bidentate ligands, have received less attention [7 ± 9]. They are, however, versatile ligands whose coordinative abilities could be influenced by the nature of additional substituents at the 3 and/or 5 position of the pyrazole ring.In this context, it is interesting to note that a (pyridinylpyrazole)-type ligand such as 5-methyl-1-(pyridin-2-yl)-1H-pyrazole-3-carboxamide (L c ) formed Cu II compounds of formula [CuX 2 (L c ) 2 ¥ H 2 O] (X Cl, Br, NO 3 , ClO 4 ) with a distorted octahedral geometry [10]. To achieve that, one of the two L c ligands acted in a N,N'-bidentate and the other in a N,N',O-tridentate fashion with the amide O-atom participating in the latter case and the sixth apical coordination site being occupied by a H 2 O molecule or a X counterion [10]. However, a related [Cu(La) 2 ] 2 complex with the 3-(2,5-dimethoxyphenyl)-1-(pyridin-2-yl)-1H-pyrazole (L a ) ligand showed a tetrahedrically distorted planar geometry in which, in addition to the CuN 4 core, CuÀO interactions with the MeO groups of each ligand were observed [11].From these results, it appears that O-containing substituents at the 3 and 5 positions of the pyrazole ring of the pyridinylpyrazole ligands can play an important role in the stereochemistry of the copper derivatives.Following these precedents, we are now interested in using O-containing 3,5-disubstituted pyridinylpyrazole ligands in metal complexes to produce different geometries that might allow access to certain types of supramolecular arrangements.

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Structure determination, spectroscopic characterization, and magnetic properties of a novel dinuclear copper(II) crown ether bipyridine complex

Cited by 28 publications

References 9 publications

Study of the PVA hydrogel behaviour in 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid

Study of the PVA hydrogel behaviour in 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid

Syntheses, Electronic Absorption, Emission, and Ion-Binding Studies of Platinum(II) C^N^C and Terpyridyl Complexes Containing Crown Ether Pendants

Copper Complexes with New Pyridylpyrazole Based Ligands

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