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Del Gobbo J, Santini C, Dolmella A, Li Z, Caviglia M, Pellei M. New Copper Complexes with N,O-Donor Ligands Based on Pyrazole Moieties Supported by 3-Substituted Acetylacetone Scaffolds. Molecules 2024; 29:621. [PMID: 38338366 PMCID: PMC10856362 DOI: 10.3390/molecules29030621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 01/20/2024] [Accepted: 01/26/2024] [Indexed: 02/12/2024] Open
Abstract
The new 3-monosubstituted acetylacetone ligands, 3-(phenyl(1H-pyrazol-1-yl)methyl)pentane-2,4-dione (HLacPz) and 3-((3,5-dimethyl-1H-pyrazol-1-yl)(phenyl)methyl)pentane-2,4-dione (HLacPzMe), were synthesized and used as supporting ligands for new copper(II) and copper(I) phosphane complexes of the general formulae [Cu(HLacX)2(LacX)2] and [Cu(PPh3)2(HLacX)]PF6 (X = Pz (pyrazole) or PzMe (3,5-dimethylpyrazole)), respectively. In the syntheses of the Cu(I) complexes, the triphenylphosphine coligand (PPh3) was used to stabilize copper in the +1 oxidation state, avoiding oxidation to Cu(II). All compounds were characterized by CHN analysis, 1H-NMR, 13C-NMR, FT-IR spectroscopy, and electrospray ionization mass spectrometry (ESI-MS). The ligands HLacPz (1) and HLacPzMe (2) and the copper complex [Cu(PPh3)2(HLacPz)]PF6 (3) were also characterized by X-ray crystallography. The reactivity of these new compounds was investigated and the new compounds 4-phenyl-4-(1H-pyrazol-1-yl)butan-2-one (7) and 4-(3,5-dimethyl-1H-pyrazol-1-yl)-4-phenylbutan-2-one (8) were obtained in basic conditions via the retro-Claisen reaction of related 3-monosubstituted acetylacetone, providing efficient access to synthetically useful ketone compounds. Compound 8 was also characterized by X-ray crystallography.
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Affiliation(s)
- Jo’ Del Gobbo
- School of Science and Technology, Chemistry Division, University of Camerino, Via Madonna delle Carceri (ChIP), Camerino, 62032 Macerata, Italy; (J.D.G.); (C.S.); (Z.L.); (M.C.)
| | - Carlo Santini
- School of Science and Technology, Chemistry Division, University of Camerino, Via Madonna delle Carceri (ChIP), Camerino, 62032 Macerata, Italy; (J.D.G.); (C.S.); (Z.L.); (M.C.)
| | - Alessandro Dolmella
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Via Marzolo 5, 35131 Padova, Italy
| | - Zhenzhen Li
- School of Science and Technology, Chemistry Division, University of Camerino, Via Madonna delle Carceri (ChIP), Camerino, 62032 Macerata, Italy; (J.D.G.); (C.S.); (Z.L.); (M.C.)
| | - Miriam Caviglia
- School of Science and Technology, Chemistry Division, University of Camerino, Via Madonna delle Carceri (ChIP), Camerino, 62032 Macerata, Italy; (J.D.G.); (C.S.); (Z.L.); (M.C.)
| | - Maura Pellei
- School of Science and Technology, Chemistry Division, University of Camerino, Via Madonna delle Carceri (ChIP), Camerino, 62032 Macerata, Italy; (J.D.G.); (C.S.); (Z.L.); (M.C.)
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2
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Gildenast H, Hempelmann G, Gruszien L, Englert U. A Rigid Linker for Site-Selective Coordination of Transition Metal Cations: Combining an Acetylacetone with a Caged Phosphine. Inorg Chem 2023; 62:3178-3185. [PMID: 36757816 DOI: 10.1021/acs.inorgchem.2c04101] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
The combination of a soft phosphorus and a hard oxygen donor in the new ligand HacacTRIP leads to excellent site selectivity for the coordination of two different metal cations of matching Pearson character. The deprotonation step required for coordinating the acetylacetone oxygen donor further increases the selectivity. In contrast to most phosphines, the use of the caged phosphatriptycene motif enables a rigid and directional orientation of the phosphorus binding site which is required to form stable coordination network structures. In addition to the synthesis of HacacTRIP, we present its selective coordination. The deprotonated acetylacetone was selectively bound to CuII and FeIII. The solid state structure of the former displays a rare axial coordination of chloroform molecules. The phosphorus donor was selectively coordinated to the monovalent coinage metal cations CuI, AgI, and AuI. The CuI and AgI complexes represent the first examples in which a phosphatriptycene is bound to these metal cations. Heterometallic coordination compounds were characterized with combinations of these two groups. They comprise an oligonuclear CuI/CuII mixed-valence compound in which iodide binds to both CuI and CuII cations and a complex in which acacTRIP- bridges CuII and AuI. In addition to these discrete aggregates, the ligand has been used to link FeIII and AgI into a 2D coordination polymer with unprecedented trigonal planar coordination of three bulky phosphatriptycenes to a cation and resulting honeycomb topology. Its almost regular hexagons underline the desired rigidity of the ditopic acacTRIP- ligand.
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Affiliation(s)
- Hans Gildenast
- RWTH Aachen University, Institute of Inorganic Chemistry, Aachen, North Rhine-Westphalia 52074, Germany
| | - Greta Hempelmann
- RWTH Aachen University, Institute of Inorganic Chemistry, Aachen, North Rhine-Westphalia 52074, Germany
| | - Lukas Gruszien
- RWTH Aachen University, Institute of Inorganic Chemistry, Aachen, North Rhine-Westphalia 52074, Germany
| | - Ulli Englert
- RWTH Aachen University, Institute of Inorganic Chemistry, Aachen, North Rhine-Westphalia 52074, Germany.,Shanxi University, Key Laboratory of Materials for Energy Conversion and Storage, Institute of Molecular Science, Taiyuan, Shanxi 030006, China
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3
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Solvent-driven self-assembly of two novel di- and tetra-nuclear Cu(II) bis(salamo)-based complexes. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.134554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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4
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van Terwingen S, Ebel B, Wang R, Englert U. Weaving a 2D net of hydrogen and halogen bonds: cocrystal of a pyrazolium bromide with tetrafluorodiiodobenzene. Acta Crystallogr C Struct Chem 2022; 78:324-331. [PMID: 35662131 PMCID: PMC9167629 DOI: 10.1107/s2053229622004648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 05/02/2022] [Indexed: 11/10/2022] Open
Abstract
Hydrohalides of Lewis bases may act as halogen bond (XB) acceptors and combine two directional interactions, namely, hydrogen bonds (HB) and XBs in the same solid. 3-(1,3,5-Trimethyl-1H-pyrazol-4-yl)acetylacetone (C11H16N2O2, HacacMePz) was protonated with HX (X = Cl or Br) to afford the hydrohalides, C11H17N2O2
+·X
− or H2acacMePz+·X
− (1, X = Cl; 2, X = Br). Hydrohalides 1 and 2 are isomorphous and adopt a classical dipole packing. Consistent with the observation for most β-diketones, the enol form with an intramolecular HB is observed. Additional noteworthy interactions are HBs of the protonated pyrazolium towards the X
− anion at donor–acceptor distances of 2.9671 (17) Å for 1 and 3.159 (4) Å for 2. Cocrystallization of hydrobromide 2 with the XB donor tetrafluorodiiodobenzene (TFDIB) leads to the adduct C11H17N2O2
+·Br−·0.5C6F4I2·H2O or (H2acacMePz+·Br−)2·(H2O)2·TFDIB (3), in which the XB donor TFDIB is situated on a crystallographic centre of inversion. Classical HBs link organic cations, water molecules and Br− anions into chains along [010]. Almost orthogonal to this interaction, XBs with Br...I = 3.2956 (4) Å connect neighbouring chains along [102] into two-dimensional sheets in the (10\overline{2}) plane. Assisted by their negative charge, halide anions represent particularly good nucleophiles towards XB donors.
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Structural Diversity of Silver Fluorinated β-Diketonates: Effect of the Terminal Substituent and Solvent. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27030677. [PMID: 35163942 PMCID: PMC8839988 DOI: 10.3390/molecules27030677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/15/2022] [Accepted: 01/17/2022] [Indexed: 11/17/2022]
Abstract
In order to demonstrate the role of the fluorination and some solvents in the structural organization of the Ag(I) coordination polymers with β-diketonate ligands (R1C(O)CαHC(O)R2)− we synthesized a series of the compounds containing tfac- (R1 = CH3, R2 = CF3) and pfpac- (R1 = CH3, R2 = C2F5) anions. Solvent-free [Ag(L)]∞ (L = tfac 1, pfpac 2) compounds and the corresponding acetonitrile and toluene adducts have been characterized by elemental analysis and/or NMR, IR and single-crystal XRD. This series includes five new coordination polymers. Compound 1 is a 3D coordination framework based on Ag–Ochelate/bridge, Ag–Cα bonds, and argentophilic interactions. An increase in the fluorinated group leads to a chain coordination polymer 2 of an unusual structural organization. These chains can be represented as a “DNA-type”, where two intertwined helices based on Ag–Ochelate and Ag–Cα bonds are connected through Ag–Obridge ones. Two structural types of chain coordination polymers, [Ag(tfac)(CH3CN)] and [Ag2(L)2(solvent)], have been revealed for the adducts. The latter structural type differs significantly from the previously studied toluene and acetonitrile adducts of fluorinated Ag(I) β-diketonates of the same stoichiometry. Thermal analysis in helium showed that both 1 and 2 decompose to metallic silver with the compound of pfpac-ligand being slightly more stable.
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Gildenast H, Gruszien L, Friedt F, Englert U. Phosphorus or Nitrogen - The first Phosphatriptycene in Coordination Polymer Chemistry. Dalton Trans 2022; 51:7828-7837. [DOI: 10.1039/d2dt00728b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Phosphasilatriptycene, a phenylene spacer and a pyridyl moiety represent the building blocks of TRIP-Py, the first heteroditopic ligand featuring a phoshatriptycene scaffold. The P and N donor sites located at...
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van Terwingen S, Nachtigall N, Englert U. Synthesis and coordination to the coinage metals of a trimethylpyrazolyl substituted 3-arylacetylacetone. Z KRIST-CRYST MATER 2021. [DOI: 10.1515/zkri-2021-2059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The ligand 3-(4-(1,3,5-trimethyl-1H-pyrazol-4-yl)phenyl)acetylacetone (1) combines a Pearson hard O,O′ chelating acetylacetone donor with a softer pyrazole N donor bridged by a phenylene spacer. Deprotonation and coordination to CuII leads to a square planar bis-acetylacetonato complex; interpreting the close proximity of an adjacent complex’s pyrazole moiety as an
η
2
${{\eta}}^{2}$
coordination to the axial CuII position leads to a two dimensional extended structure. The N donor capabilities are proven by coordination to AgPF6 and AuCl; for AgI a cationic linear bis-pyrazole complex as a toluene solvate is obtained with toluene-pyrazole π-interactions and an essentially uncoordinated
PF
6
-
${{\mathrm{PF}}_{6}}^{-}$
anion. In the case of AuCl a neutral linear coordination compound with one chlorido and one pyrazole ligand 1 is obtained. Comparing the dihedral angles with a closely related but shorter ligand reveals a larger rotational degree of freedom in 1, allowing for richer architectures in emerging coordination polymers.
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Affiliation(s)
- Steven van Terwingen
- Institute of Inorganic Chemistry, RWTH Aachen University , Landoltweg 1, 52074 Aachen , Germany
| | - Noah Nachtigall
- Institute of Inorganic Chemistry, RWTH Aachen University , Landoltweg 1, 52074 Aachen , Germany
| | - Ulli Englert
- Institute of Inorganic Chemistry, RWTH Aachen University , Landoltweg 1, 52074 Aachen , Germany
- Shanxi University, Institute of Molecular Science , Taiyuan , Shanxi 030006 , People’s Republic of China
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8
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Dong L, Guo YF, Ma JY, Wang JL, Feng SX, Huo HK. Crystal structure of (E)-3-((4-(tert-butyl)phenyl)thio)-4-hydroxypent-3-en-2-one, C15H20O2S. Z KRIST-NEW CRYST ST 2021. [DOI: 10.1515/ncrs-2021-0365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C15H20O2S, monoclinic, P21/c (No. 14), a = 12.8520(8) Å, b = 10.5864(8) Å, c = 11.2202(7) Å, β = 104.375(7)°, V = 1478.78(18) Å3, Z = 4, R
gt
(F) = 0.0655, wR
ref
(F
2) = 0.1781, T = 293 K.
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Affiliation(s)
- Le Dong
- School of Chemical Engineering and Pharmaceutics, Henan University of Science and Technology , Luoyang , Henan 471003 , P. R. China
| | - Ya-Fei Guo
- School of Chemical Engineering and Pharmaceutics, Henan University of Science and Technology , Luoyang , Henan 471003 , P. R. China
| | - Jun-Ying Ma
- School of Chemical Engineering and Pharmaceutics, Henan University of Science and Technology , Luoyang , Henan 471003 , P. R. China
| | - Jun-Ling Wang
- School of Chemical Engineering and Pharmaceutics, Henan University of Science and Technology , Luoyang , Henan 471003 , P. R. China
| | - Shu-Xiao Feng
- School of Chemical Engineering and Pharmaceutics, Henan University of Science and Technology , Luoyang , Henan 471003 , P. R. China
| | - Hui-Kang Huo
- School of Chemical Engineering and Pharmaceutics, Henan University of Science and Technology , Luoyang , Henan 471003 , P. R. China
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van Terwingen S, Brüx D, Wang R, Englert U. Hydrogen-Bonded and Halogen-Bonded: Orthogonal Interactions for the Chloride Anion of a Pyrazolium Salt. Molecules 2021; 26:3982. [PMID: 34210096 PMCID: PMC8272125 DOI: 10.3390/molecules26133982] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/25/2021] [Accepted: 06/25/2021] [Indexed: 11/21/2022] Open
Abstract
In the hydrochloride of a pyrazolyl-substituted acetylacetone, the chloride anion is hydrogen-bonded to the protonated pyrazolyl moiety. Equimolar co-crystallization with tetrafluorodiiodobenzene (TFDIB) leads to a supramolecular aggregate in which TFDIB is situated on a crystallographic center of inversion. The iodine atom in the asymmetric unit acts as halogen bond donor, and the chloride acceptor approaches the σ-hole of this TFDIB iodine subtending an almost linear halogen bond, with Cl···I = 3.1653(11) Å and Cl···I-C = 179.32(6)°. This contact is roughly orthogonal to the N-H···Cl hydrogen bond. An analysis of the electron density according to Bader's Quantum Theory of Atoms in Molecules confirms bond critical points (bcps) for both short contacts, with ρbcp = 0.129 for the halogen and 0.321eÅ-3 for the hydrogen bond. Our halogen-bonded adduct represents the prototype for a future class of co-crystals with tunable electron density distribution about the σ-hole contact.
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Affiliation(s)
- Steven van Terwingen
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany; (S.v.T.); (D.B.); (R.W.)
| | - Daniel Brüx
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany; (S.v.T.); (D.B.); (R.W.)
| | - Ruimin Wang
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany; (S.v.T.); (D.B.); (R.W.)
- Institute of Molecular Science, Shanxi University, Taiyuan 030006, China
| | - Ulli Englert
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany; (S.v.T.); (D.B.); (R.W.)
- Institute of Molecular Science, Shanxi University, Taiyuan 030006, China
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10
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Gildenast H, Nölke S, Englert U. 3-(4-Methylthiophenyl)acetylacetone – ups and downs of flexibility in the synthesis of mixed metal–organic frameworks. Ditopic bridging of hard and soft cations and site-specific desolvation. CrystEngComm 2020. [DOI: 10.1039/c9ce01932d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Different Pearson-hardness of O and S donors leads to well-ordered mixed metal–organic frameworks.
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Affiliation(s)
- Hans Gildenast
- RWTH Aachen University
- Institute of Inorganic Chemistry
- 52074 Aachen
- Germany
| | - Stephanie Nölke
- RWTH Aachen University
- Institute of Inorganic Chemistry
- 52074 Aachen
- Germany
| | - Ulli Englert
- RWTH Aachen University
- Institute of Inorganic Chemistry
- 52074 Aachen
- Germany
- Key Laboratory of Materials for Energy Conversion and Storage
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Wang A, Englert U. Absolute structure of the chiral pyrrolidine derivative (2S)-methyl (Z)-5-(2-tert-butoxy-1-cyano-2-oxoethylidene)pyrrolidine-2-carboxylate, a compound with low resonant scattering. Acta Crystallogr C Struct Chem 2019; 75:1448-1453. [PMID: 31686652 PMCID: PMC6829528 DOI: 10.1107/s2053229619012324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 09/04/2019] [Indexed: 07/22/2024] Open
Abstract
The enantiopure monopyrrolidine derivative (2S)-methyl (Z)-5-(2-tert-butoxy-1-cyano-2-oxoethylidene)pyrrolidine-2-carboxylate, C13H18N2O4, (1), represents a potential ligand and an attractive intermediate for the synthesis of chiral metal complexes. At the molecular level, the compound features an intramolecular N-H...O hydrogen bond; neighbouring molecules interact via N-H...N contacts to form chains along [100]. Due to its elemental composition, resonant scattering of the target compound is entirely insignificant for diffraction experiments with Mo Kα and small even for Cu Kα radiation. A preliminary study with the harder radiation type confirmed the chiral space group and the suitability of the single crystal chosen; as expected, the results concerning the absolute structure remained completely inconclusive. A second data collection with the longer wavelength gave satisfactory quality indicators for the correct handedness of the molecule, albeit with high standard uncertainties. The absolute configuration has been assessed independently: CD spectra for both enantiomers of the target molecule were calculated and the spectrum for the S-configured stereoisomer was in agreement with the experiment. The Cotton effect of (1) may be ascribed to π-π* transitions from HOMO to LUMO and from HOMO to LUMO+1. As both independent techniques agree with respect to the handedness of the target molecule, the absolute structure may be assigned with a high degree of confidence.
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Affiliation(s)
- Ai Wang
- Key Laboratory of Materials for Energy Conversion and Storage, Institute of Molecular Science, Shanxi University, Taiyuan, Shanxi 030006, People’s Republic of China
| | - Ulli Englert
- Key Laboratory of Materials for Energy Conversion and Storage, Institute of Molecular Science, Shanxi University, Taiyuan, Shanxi 030006, People’s Republic of China
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
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12
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Wang R, George J, Potts SK, Kremer M, Dronskowski R, Englert U. The many flavours of halogen bonds - message from experimental electron density and Raman spectroscopy. Acta Crystallogr C Struct Chem 2019; 75:1190-1201. [PMID: 31484805 PMCID: PMC6727171 DOI: 10.1107/s205322961901132x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 08/13/2019] [Indexed: 11/10/2022] Open
Abstract
Experimental electron-density studies based on high-resolution diffraction experiments allow halogen bonds between heavy halogens to be classified. The topological properties of the electron density in Cl...Cl contacts vary smoothly as a function of the interaction distance. The situation is less straightforward for halogen bonds between iodine and small electronegative nucleophiles, such as nitrogen or oxygen, where the electron density in the bond critical point does not simply increase for shorter distances. The number of successful charge-density studies involving iodine is small, but at least individual examples for three cases have been observed. (a) Very short halogen bonds between electron-rich nucleophiles and heavy halogen atoms resemble three-centre-four-electron bonds, with a rather symmetric heavy halogen and without an appreciable σ hole. (b) For a narrow intermediate range of halogen bonds, the asymmetric electronic situation for the heavy halogen with a pronounced σ hole leads to rather low electron density in the (3,-1) critical point of the halogen bond; the properties of this bond critical point cannot fully describe the nature of the associated interaction. (c) For longer and presumably weaker contacts, the electron density in the halogen bond critical point is only to a minor extent reduced by the presence of the σ hole and hence may be higher than in the aforementioned case. In addition to the electron density and its derived properties, the halogen-carbon bond distance opposite to the σ hole and the Raman frequency for the associated vibration emerge as alternative criteria to gauge the halogen-bond strength. We find exceptionally long C-I distances for tetrafluorodiiodobenzene molecules in cocrystals with short halogen bonds and a significant red shift for their Raman vibrations.
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Affiliation(s)
- Ruimin Wang
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, Aachen 52056, Germany
- Institute of Molecular Science, Shanxi University, Taiyuan, Shanxi 030006, People’s Republic of China
| | - Janine George
- Institute of Condensed Matter and Nanosciences, Chemin des Étoiles 8/L7.03.01, Louvain-la-Neuve 1348, Belgium
| | - Shannon Kimberly Potts
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, Aachen 52056, Germany
| | - Marius Kremer
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, Aachen 52056, Germany
| | - Richard Dronskowski
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, Aachen 52056, Germany
- Jlich-Aachen Research Alliance (JARA-HPC), RWTH Aachen University, Aachen 52056, Germany
- Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic, 7098 Liuxian Blvd, Shenzhen, People’s Republic of China
| | - Ulli Englert
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, Aachen 52056, Germany
- Institute of Molecular Science, Shanxi University, Taiyuan, Shanxi 030006, People’s Republic of China
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13
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Argentophilic Interactions in Two AgI Complexes of 3-(2-(Pyridin-4-yl)ethyl)pentane-2,4-dione, a Promising Ditopic Ligand. CRYSTALS 2019. [DOI: 10.3390/cryst9080414] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Reactions of 3-(2-(pyridin-4-yl)ethyl)pentane-2,4-dione (HacacPyen) with AgPF6 and AgBF4 afforded cationic silver complexes [Ag(HacacPyen)2]+ with essentially linear coordination of the Ag I cation by two pyridine N atoms. Rather unexpectedly, the HacacPyen ligands in the PF6- salt 1 adopt the diketo form, in contrast to the uncoordinated HacacPyen molecule, whereas the corresponding BF4- salt 2 and the majority of 3-substituted acetylacetones crystallizes as the enol tautomer. In both compounds 1 and 2, complex cations aggregate via short Ag...Ag interactions to pairs. These contacts amount to 3 . 21 Å in 1 and 3 . 26 Å or 3 . 31 Å in 2. As they are unsupported by any additional bridging ligands and correspond to the closest interionic interactions between neighbouring complex cations, they may be addressed as argentophilic interactions. The PF6- anions in 1 and the BF4- counter ions in 2 are involved in long and presumably electrostatic Ag...F contacts of ca. 2 . 9 Å. Additional coordination between Ag I and keto O atoms of symmetry-equivalent ligands occurs in 1 and leads to an extended two-periodic supramolecular structure.
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14
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Truong KN, Meven M, Englert U. Proton disorder in a short intramolecular hydrogen bond investigated by single-crystal neutron diffraction at 2.5 and 170 K. ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY 2018; 74:1635-1640. [PMID: 30516147 DOI: 10.1107/s2053229618015164] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 10/26/2018] [Indexed: 11/10/2022]
Abstract
The substituted acetylacetone 3-[2-(pyridin-4-yl)ethyl]pentane-2,4-dione, C12H15NO2, (1), with an ethylene bridge between the acetylacetone moiety and the heteroaromatic ring, represents an attractive linker for mixed-metal coordination polymers. In the crystal, (1) adopts an antiperiplanar conformation with respect to the C-C bond in the central ethylene group and almost coplanar acetylacetone and pyridyl groups. The ditopic molecule exists as the enol tautomer, with proton disorder in the short intramolecular hydrogen bond. Single-crystal neutron diffraction at 2.5 K indicated site occupancies of 0.602 (17) and 0.398 (17). The geometry of the acetylacetone moiety is in agreement with such a site preference of the bridging hydrogen: the O atom associated with the preferred H-atom site subtends the longer [1.305 (2) Å] and the more carbonyl-like O atom the shorter [1.288 (2) Å] C-O bond. Based on structure-factor calculations for the alternative H-atom sites, reflections particularly sensitive for proton distribution were identified and measured in a second neutron data collection at 170 K. At this temperature, 546 independent neutron intensities were used to refine positional and isotropic displacement parameters for a structure model in which parameters for C and O atoms were constrained to those obtained by single-crystal X-ray diffraction at the same temperature. The site occupancies for the disordered proton do not significantly differ from those at 2.5 K.
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Affiliation(s)
- Khai Nghi Truong
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Martin Meven
- Institute of Crystallography, RWTH Aachen University, and Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (FRM-II), Lichtenbergstrasse 1, 85748 Garching, Germany
| | - Ulli Englert
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
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