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Metallacrown

April 13, 2024

In chemistry, metallacrowns are a macrocyclic compounds that consist of metal ions and solely or predominantly heteroatoms in the ring. Classically, metallacrowns contain an [M–N–O] repeat unit in the macrocycle. First discovered by Vincent L. Pecoraro and Myoung Soo Lah in 1989,[1] metallacrowns are best described as inorganic analogues of crown ethers. To date, over 600 reports of metallacrown research have been published. Metallacrowns with sizes ranging from 12-MC-4 to 60-MC-20 have been synthesized.[2]

Figure showing the metallacrown analogy to the organic crown ether. Ligand substituents are omitted for clarity.
a) 12-Crown-4 b) 12-MCFe(III)N(shi)-4
c) 15-Crown-5 d) 15-MCCu(II)N(picHA)-5

Nomenclature edit

Metallacrown nomenclature has been developed to mimic the nomenclature of crown ethers, which are named by the total number of atoms in the ring, followed by "C" for "crown," and the number of oxygen atoms in the ring. For example, 12-crown-4 or 12-C-4 describes Figure 2a. When naming metallacrowns, a similar format is followed. However, the C becomes "MC" for "metallacrown" and the "MC" is followed by the ring metal, other heteroatom, and the ligand used to make the metallacrown. For example, metallacrown b in the figure above is named [12-MCFe(III)N(shi)-4], where "shi" is the ligand, salicylhydroxamic acid.[2]

Preparation edit

Metallacrowns form via self-assembly, i.e. by dissolving the ligand in a solvent followed by the desired metal salt. The first reported metallacrown was MnII(OAc)2(DMF)6[12-MCMn(III)N(shi)-4].[1] Metallacrowns can be prepared with a variety of metals in the ring and in a variety of ring sizes.[2] Many metallacrowns have been prepared, including 9-MC-3, 15-MC-5, and 18-MC-6. Ring size is controlled by a number of factors, such as the geometry of the ligand chelate ring, ring metal Jahn–Teller distortion, central metal size, steric effects, and stoichiometry. Common ring metals have included V(III), Mn(III), Fe(III), Ni(II) and Cu(II). Hydroxamic acids, such as salicylhydroxamic acid, and oximes are commonly utilized in metallacrown ligands.

Structure edit

Many structures have been characterized by single-crystal X-ray crystallography. Metallacrowns typically contain fused chelate rings in their structure, which imparts them with substantial stability. Metallacrowns have been synthesized with substantial variety. Mixed ligand and mixed ring-metal, and mixed-oxidation state metallacrowns are known. Inverse metallacrowns have been reported that contain metal ions oriented towards the center of the ring.[3] Metallacryptates, metallahelicates, and fused metallacrowns are known.[2] Among the interesting features of metallacrowns are the similarities between certain structures and the corresponding crown ether. For example, in the 12-C-4, the cavity size is 2.79 Å and the bite distance is 0.6 Å. In the 12-MC-4, the cavity size is 2.67 Å and the bite distance is 0.5 Å.[1]

Properties edit

Metallacrowns are most widely studied for their potential use as SMMs (single-molecule magnets). Notably, the first mixed manganese-lanthanide SMM was a metallacrown.[4] Metallacrowns with gadolinium as the central metal are potential MRI contrast agents.[5][6] A lot of attention is focused on metallacrown molecular recognition and host–guest chemistry.[7] Chelation of heavy metals by 15-MC-5 complexes could be utilized in lanthanide separation or heavy metal sequestration.[8] Metallacrown container molecules constructed from the 15-MC-5 structure type have been shown to selectively encapsulate carboxylate anions in hydrophobic cavities.[9][10][11] A crystalline solid displaying second-harmonic generation was generated by including a nonlinear optical chromophore in a chiral metallacrown compartment.[12] Metallacrowns have also been utilized in the construction of microporous.[13][14] and mesoporous materials.[15] In another potential application, some metallacrowns exhibit antibacterial activity.[16]

References edit

  1. ^ a b c Lah, M. S.; V. L., Pecoraro (1989). "Isolation and Characterization of {MnII[MnIII(salicylhydroximate)]4(acetate)2(DMF)6}∙2DMF: An Inorganic Analogue of M2+(12-crown-4)". J. Am. Chem. Soc. 111 (18): 7258. doi:10.1021/ja00200a054.
  2. ^ a b c d Mezei, G.; Zaleski, C. M.; V. L., Pecoraro (2007). "Structural and functional evolution of metallacrowns". Chem. Rev. 107 (11): 4933–5003. doi:10.1021/cr078200h. PMID 17999555.
  3. ^ Stemmler, A. J.; Kampf, J. W. and Pecoraro, V. L. "Synthesis and Crystal Structure of The First Inverse 12-Metallacrown-4" Inorg. Chem., 1995, 34, 2271-2272.
  4. ^ Zaleski, Curtis M.; Depperman, Ezra C.; Kampf, Jeff W.; Kirk, Martin L.; Pecoraro, Vincent L. (2004). "Synthesis, Structure, and Magnetic Properties of a Large Lanthanide–Transition-Metal Single-Molecule Magnet". Angew. Chem. Int. Ed. 43 (30): 3912–3914. doi:10.1002/anie.200454013. PMID 15274211.
  5. ^ Stemmler, Ann J.; Kampf, Jeff W.; Kirk, Martin L.; Atasi, Bassel H.; Pecoraro, Vincent L. (1999). "The Preparation, Characterization, and Magnetism of Copper 15-Metallacrown-5 Lanthanide Complexes". Inorganic Chemistry. 38 (12): 2807–2817. doi:10.1021/ic9800233. ISSN 0020-1669. PMID 11671025.
  6. ^ Parac-Vogt, Tatjana N.; Pacco, Antoine; Nockemann, Peter; Laurent, Sophie; Muller, Robert N.; Wickleder, Mathias; Meyer, Gerd; Vander Elst, Luce; Binnemans, Koen (2005). "Relaxometric Study of Copper [15]Metallacrown-5 Gadolinium Complexes Derived from alpha-Aminohydroxamic Acids". Chem. Eur. J. 12 (1): 204–210. doi:10.1002/chem.200500136. PMID 16267864.
  7. ^ Stemmler, A. J.; Kampf, J. W.; Pecoraro, V. L. (1996). "A Planar [15]Metallacrown-5 That Selectivity Binds the Uranyl Cation". Angew. Chem. Int. Ed. 35 (2324): 2841. doi:10.1002/anie.199628411.
  8. ^ Tegoni, M.; Furlotti, M.; Tropiano, M.; Lim, C. S.; Pecoraro, V. L. (2010). "Thermodynamics of Core Metal Replacement and Self-Assembly of Ca2+ 15-Metallacrown-5". Inorg. Chem. 49 (11): 5190–5201. doi:10.1021/ic100315u. PMID 20429607.
  9. ^ Tegoni, M.; Tropiano, M.; Marchiò, L. (2009). "Thermodynamics of binding of carboxylates to amphiphilic Eu3+/Cu2+ metallacrown". Dalton Trans. 2009 (34): 6705–6708. doi:10.1039/b911512a. PMID 19690677. S2CID 36101938.
  10. ^ Lim, C. S.; Kampf, J. W.; Pecoraro, V. L. (2009). "Establishing the binding affinity of organic carboxylates to 15-metallacrown-5 complexes". Inorg. Chem. 48 (12): 5224–5233. doi:10.1021/ic9001829. PMID 19499955.
  11. ^ Jankolovits, Joseph; Kampf, Jeff W.; Maldonado, Stephen; Pecoraro, Vincent L. (2010). "Voltammetric Characterization of Redox-Inactive Guest Binding to LnIII[15-Metallacrown-5] Hosts Based on Competition with a Redox Probe" (PDF). Chem. Eur. J. 16 (23): 6786–6796. doi:10.1002/chem.200903015. hdl:2027.42/77442. PMID 20468028.
  12. ^ Mezei, Gellert; Kampf, Jeff W.; Pan, Shilie; Poeppelmeier, Kenneth R.; Watkins, Byron; Pecoraro, Vincent L. (2007). "Metallacrown-based compartments: selective encapsulation of three isonicotinate anions in non-centrosymmetric solids". Chem. Comm. (11): 1148–1150. doi:10.1039/b614024f. PMID 17347721. S2CID 2622757.
  13. ^ Bodwin, J. J.; Pecoraro, V. L. (2000). "Preparation of a Chiral, 2-Dimensional Network Containing Metallacrown and Copper Benzoate Building Blocks". Inorg. Chem. 39 (16): 3434–3435. doi:10.1021/ic000562j. PMID 11196797.
  14. ^ Moon, M.; Kim, I.; Lah, M. S. (2000). "Three-Dimensional Framework Constructed Using Nanometer-Sized Metallamacrocycle as a Secondary Building Unit". Inorg. Chem. 39 (13): 2710–2711. doi:10.1021/ic991079f. PMID 11232804.
  15. ^ Lim, Choong-Sun; Jankolovits, Joseph; Kampf, Jeff W.; Pecoraro, Vincent L. (2010). "Chiral Metallacrown Supramolecular Compartments that Template Nanochannels: Self-Assembly and Guest Absorption" (PDF). Chem. Asian J. 5 (1): 46–49. doi:10.1002/asia.200900612. hdl:2027.42/64519. PMID 19950345.
  16. ^ Dendrinou-Samara, C.; Papadopoulos, A. N.; Malamatari, D. A.; Tarushi, A.; Raptopoulou, C. P.; Terzis, A.; Samaras, E.; Kessissoglou, D. P. (2005). "Inter-conversion of 15-MC-5 to 12-MC-4 manganese metallacrowns: structure and bioactivity of metallacrowns hosting carboxylato complexes". J. Inorg. Biochem. 99 (3): 864–75. doi:10.1016/j.jinorgbio.2004.12.021. PMID 15708808.

April 13, 2024
metallacrown, chemistry, metallacrowns, macrocyclic, compounds, that, consist, metal, ions, solely, predominantly, heteroatoms, ring, classically, metallacrowns, contain, repeat, unit, macrocycle, first, discovered, vincent, pecoraro, myoung, 1989, metallacrow. In chemistry metallacrowns are a macrocyclic compounds that consist of metal ions and solely or predominantly heteroatoms in the ring Classically metallacrowns contain an M N O repeat unit in the macrocycle First discovered by Vincent L Pecoraro and Myoung Soo Lah in 1989 1 metallacrowns are best described as inorganic analogues of crown ethers To date over 600 reports of metallacrown research have been published Metallacrowns with sizes ranging from 12 MC 4 to 60 MC 20 have been synthesized 2 Figure showing the metallacrown analogy to the organic crown ether Ligand substituents are omitted for clarity a 12 Crown 4 b 12 MCFe III N shi 4c 15 Crown 5 d 15 MCCu II N picHA 5 Contents 1 Nomenclature 2 Preparation 3 Structure 4 Properties 5 ReferencesNomenclature editMetallacrown nomenclature has been developed to mimic the nomenclature of crown ethers which are named by the total number of atoms in the ring followed by C for crown and the number of oxygen atoms in the ring For example 12 crown 4 or 12 C 4 describes Figure 2a When naming metallacrowns a similar format is followed However the C becomes MC for metallacrown and the MC is followed by the ring metal other heteroatom and the ligand used to make the metallacrown For example metallacrown b in the figure above is named 12 MCFe III N shi 4 where shi is the ligand salicylhydroxamic acid 2 Preparation editMetallacrowns form via self assembly i e by dissolving the ligand in a solvent followed by the desired metal salt The first reported metallacrown was MnII OAc 2 DMF 6 12 MCMn III N shi 4 1 Metallacrowns can be prepared with a variety of metals in the ring and in a variety of ring sizes 2 Many metallacrowns have been prepared including 9 MC 3 15 MC 5 and 18 MC 6 Ring size is controlled by a number of factors such as the geometry of the ligand chelate ring ring metal Jahn Teller distortion central metal size steric effects and stoichiometry Common ring metals have included V III Mn III Fe III Ni II and Cu II Hydroxamic acids such as salicylhydroxamic acid and oximes are commonly utilized in metallacrown ligands Structure editMany structures have been characterized by single crystal X ray crystallography Metallacrowns typically contain fused chelate rings in their structure which imparts them with substantial stability Metallacrowns have been synthesized with substantial variety Mixed ligand and mixed ring metal and mixed oxidation state metallacrowns are known Inverse metallacrowns have been reported that contain metal ions oriented towards the center of the ring 3 Metallacryptates metallahelicates and fused metallacrowns are known 2 Among the interesting features of metallacrowns are the similarities between certain structures and the corresponding crown ether For example in the 12 C 4 the cavity size is 2 79 A and the bite distance is 0 6 A In the 12 MC 4 the cavity size is 2 67 A and the bite distance is 0 5 A 1 Properties editMetallacrowns are most widely studied for their potential use as SMMs single molecule magnets Notably the first mixed manganese lanthanide SMM was a metallacrown 4 Metallacrowns with gadolinium as the central metal are potential MRI contrast agents 5 6 A lot of attention is focused on metallacrown molecular recognition and host guest chemistry 7 Chelation of heavy metals by 15 MC 5 complexes could be utilized in lanthanide separation or heavy metal sequestration 8 Metallacrown container molecules constructed from the 15 MC 5 structure type have been shown to selectively encapsulate carboxylate anions in hydrophobic cavities 9 10 11 A crystalline solid displaying second harmonic generation was generated by including a nonlinear optical chromophore in a chiral metallacrown compartment 12 Metallacrowns have also been utilized in the construction of microporous 13 14 and mesoporous materials 15 In another potential application some metallacrowns exhibit antibacterial activity 16 References edit a b c Lah M S V L Pecoraro 1989 Isolation and Characterization of MnII MnIII salicylhydroximate 4 acetate 2 DMF 6 2DMF An Inorganic Analogue of M2 12 crown 4 J Am Chem Soc 111 18 7258 doi 10 1021 ja00200a054 a b c d Mezei G Zaleski C M V L Pecoraro 2007 Structural and functional evolution of metallacrowns Chem Rev 107 11 4933 5003 doi 10 1021 cr078200h PMID 17999555 Stemmler A J Kampf J W and Pecoraro V L Synthesis and Crystal Structure of The First Inverse 12 Metallacrown 4 Inorg Chem 1995 34 2271 2272 Zaleski Curtis M Depperman Ezra C Kampf Jeff W Kirk Martin L Pecoraro Vincent L 2004 Synthesis Structure and Magnetic Properties of a Large Lanthanide Transition Metal Single Molecule Magnet Angew Chem Int Ed 43 30 3912 3914 doi 10 1002 anie 200454013 PMID 15274211 Stemmler Ann J Kampf Jeff W Kirk Martin L Atasi Bassel H Pecoraro Vincent L 1999 The Preparation Characterization and Magnetism of Copper 15 Metallacrown 5 Lanthanide Complexes Inorganic Chemistry 38 12 2807 2817 doi 10 1021 ic9800233 ISSN 0020 1669 PMID 11671025 Parac Vogt Tatjana N Pacco Antoine Nockemann Peter Laurent Sophie Muller Robert N Wickleder Mathias Meyer Gerd Vander Elst Luce Binnemans Koen 2005 Relaxometric Study of Copper 15 Metallacrown 5 Gadolinium Complexes Derived from alpha Aminohydroxamic Acids Chem Eur J 12 1 204 210 doi 10 1002 chem 200500136 PMID 16267864 Stemmler A J Kampf J W Pecoraro V L 1996 A Planar 15 Metallacrown 5 That Selectivity Binds the Uranyl Cation Angew Chem Int Ed 35 2324 2841 doi 10 1002 anie 199628411 Tegoni M Furlotti M Tropiano M Lim C S Pecoraro V L 2010 Thermodynamics of Core Metal Replacement and Self Assembly of Ca2 15 Metallacrown 5 Inorg Chem 49 11 5190 5201 doi 10 1021 ic100315u PMID 20429607 Tegoni M Tropiano M Marchio L 2009 Thermodynamics of binding of carboxylates to amphiphilic Eu3 Cu2 metallacrown Dalton Trans 2009 34 6705 6708 doi 10 1039 b911512a PMID 19690677 S2CID 36101938 Lim C S Kampf J W Pecoraro V L 2009 Establishing the binding affinity of organic carboxylates to 15 metallacrown 5 complexes Inorg Chem 48 12 5224 5233 doi 10 1021 ic9001829 PMID 19499955 Jankolovits Joseph Kampf Jeff W Maldonado Stephen Pecoraro Vincent L 2010 Voltammetric Characterization of Redox Inactive Guest Binding to LnIII 15 Metallacrown 5 Hosts Based on Competition with a Redox Probe PDF Chem Eur J 16 23 6786 6796 doi 10 1002 chem 200903015 hdl 2027 42 77442 PMID 20468028 Mezei Gellert Kampf Jeff W Pan Shilie Poeppelmeier Kenneth R Watkins Byron Pecoraro Vincent L 2007 Metallacrown based compartments selective encapsulation of three isonicotinate anions in non centrosymmetric solids Chem Comm 11 1148 1150 doi 10 1039 b614024f PMID 17347721 S2CID 2622757 Bodwin J J Pecoraro V L 2000 Preparation of a Chiral 2 Dimensional Network Containing Metallacrown and Copper Benzoate Building Blocks Inorg Chem 39 16 3434 3435 doi 10 1021 ic000562j PMID 11196797 Moon M Kim I Lah M S 2000 Three Dimensional Framework Constructed Using Nanometer Sized Metallamacrocycle as a Secondary Building Unit Inorg Chem 39 13 2710 2711 doi 10 1021 ic991079f PMID 11232804 Lim Choong Sun Jankolovits Joseph Kampf Jeff W Pecoraro Vincent L 2010 Chiral Metallacrown Supramolecular Compartments that Template Nanochannels Self Assembly and Guest Absorption PDF Chem Asian J 5 1 46 49 doi 10 1002 asia 200900612 hdl 2027 42 64519 PMID 19950345 Dendrinou Samara C Papadopoulos A N Malamatari D A Tarushi A Raptopoulou C P Terzis A Samaras E Kessissoglou D P 2005 Inter conversion of 15 MC 5 to 12 MC 4 manganese metallacrowns structure and bioactivity of metallacrowns hosting carboxylato complexes J Inorg Biochem 99 3 864 75 doi 10 1016 j jinorgbio 2004 12 021 PMID 15708808 Retrieved from https en wikipedia org w index php title Metallacrown amp oldid 1181802071, wikipedia, wiki, book, books, library,

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