Electronic and vibrational properties of a MOF-5 metal–organic framework: ZnO quantum dot behaviour

Bordiga, Silvia; Lamberti, Carlo; Ricchiardi, Gabriele; Regli, Laura; Bonino, Francesca; Damin, Alessandro; Lillerud, Karl Petter; Bjørgen, Morten; Zecchina, Adriano

doi:10.1039/b407246d

Cited by 495 publications

(401 citation statements)

References 27 publications

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“…Thus, the behavior of ZnO QDs within MOF-5 contributes considerably to luminescence. The ZnO QD absorption and emission spectra from electronic transitions have been investigated by Bordiga et al 19 They guessed that the luminescent behavior of MOF-5 arises from a O 2− Zn + → O − Zn + charge-transfer transition within each tetrahedral Zn 4 O 13 metal cluster, which has been described as a ZnO-like QD. The peak intensity of photoluminescence emissions of MOF-5, observed at 525 nm, was ascribed to energy harvesting and LMCT from 1,4-benzenedicarboxylate (BDC 2− ) linked to the Zn 4 O 13 cluster.…”

Section: ■ Introductionmentioning

confidence: 99%

Luminescent Properties of Metal–Organic Framework MOF-5: Relativistic Time-Dependent Density Functional Theory Investigations

et al. 2012

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The electronically excited state and luminescence property of metal−organic framework MOF-5 were investigated using relativistic density functional theory (DFT) and timedependent DFT (TDDFT). The geometry, IR spectra, and UV− vis spectra of MOF-5 in the ground state were calculated using relativistic DFT, leading to good agreement between the experimental and theoretical results. The frontier molecular orbitals and electronic configuration indicated that the luminescence mechanism in MOF-5 follows ligand-to-ligand charge transfer (LLCT), namely, π* → π, rather than emission with the ZnO quantum dot (QD) proposed by Bordiga et al. The geometry and IR spectra of MOF-5 in the electronically excited state have been calculated using the relativistic TDDFT and compared with those for the ground state. The comparison reveals that the Zn 4 O 13 QD is rigid, whereas the ligands BDC 2− are nonrigid. In addition, the calculated emission band of MOF-5 is in good agreement with the experimental result and is similar to that of the ligand H 2 BDC. The combined results confirmed that the luminescence mechanism for MOF-5 should be LLCT with little mixing of the ligandto-metal charge transfer. The reason for the MOF-5 luminescence is explained by the excellent coplanarity between the sixmembered ring consisting of zinc, oxygen, carbon, and the benzene ring.

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Section: ■ Introductionmentioning

confidence: 99%

Luminescent Properties of Metal–Organic Framework MOF-5: Relativistic Time-Dependent Density Functional Theory Investigations

et al. 2012

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“…45,46 In some cases, 19,22 materials with similar topology showed different behaviors, that might be fully understood only by coupling the structural data with spectroscopic investigation as already reported in few cases. [10][11][12][13][14]47,48 3.1. Structural Modifications: EXAFS Data.…”

Section: Effect Of Dehydration On Cpo-27-ni: Spectroscopic Studiesmentioning

confidence: 99%

“…This hybrid architecture opens the possibility to design and synthesize a great variety of new porous materials, which are in principle able to display novel functionalities that are potentially exploitable for a number of applications in catalysis, ion-exchange, nonlinear optics, as sensors, in gas separation, and/or storage. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] In this respect, possessing very low density accompanied by large surface area and accessible volume, they have been considered as very promising materials for dihydrogen molecular adsorption. [15][16][17][18] Inspired by these promising properties, Dietzel et al 19 synthesized a three-dimensional honeycomb-like metallorganic framework with Ni(II) as the metal component: Ni 2 (dhtp)(H 2 O) 2 · 8H 2 O (dhtp ) 2,5-dihydroxyterephthalic acid).…”

Section: Introductionmentioning

confidence: 99%

Local Structure of CPO-27-Ni Metallorganic Framework upon Dehydration and Coordination of NO

et al. 2008

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· 8H 2 O is a 3D network that maintains crystallinity and porosity after solvent removal. A mild thermal treatment in high vacuo at 393 K removes not only water physisorbed on the walls of the structure but also water directly coordinated to the Ni(II) sites. This procedure allows us to obtain a MOF material with honeycomb structure able to strongly coordinate NO. In this contribution the characterization of CPO-27-Ni in respect to structural (EXAFS compared to XRD), vibrational (IR and Raman) and electronic (UV, XANES, and luminescence) properties is described in the case of the as prepared sample, of the dehydrated sample and after NO interaction. NO is strongly bonded at the Ni(II) sites, forming a 1:1 adduct; its presence causes large modification of the vibrational and electronic properties of the material with respect to the dehydrated one. Quantitative data considering energetic aspects (microcalorimetric measurements) are also included. The ability of H 2 O molecules to slowly displace NO from the Ni(II) sites makes this material a promising candidate for NO delivery inside biological tissues.

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“…The valence and the conduction bands of ZnO are mainly due to O(2p) and Zn(4s) orbitals, respectively, this electronic transition can basically be described as an O 2− Zn 2+ → O − Zn + LMCT. The organic linker acts as a photon antenna that could efficiently transfer the energy to the ZnO units [46]. In addition, the PXRD patterns of each powder for 1-4 were basically identical to those of the parent compounds, indicating that these compounds are stable during photocatalysis.…”

Section: Photocatalytic Activitymentioning

confidence: 76%

Construction of Four Zn(II) Coordination Polymers Used as Catalysts for the Photodegradation of Organic Dyes in Water

et al. 2016

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Abstract:Hydrothermal reactions of Zn(OAc) 2¨2 H 2 O with flexible bipyridyl benzene ligand and three dicarboxylic derivatives gave rise to four new coordination polymers, [Zn 7 (µ 4 -O) 2 (OAc) 10 (bpmb)] n (1), [Zn(5-OH-1,3-BDC)(bpmb)] n (2), [Zn(1,2-BDC)(bpmb)] n (3) and [Zn 2 (ADB) 2 (bpmb)] n (4) (bpmb = 1,4-bis(pyridine-3-ylmethoxy)benzene, 5-OH-1,3-H 2 BDC = 5-hydroxy-1,3-benzenedicarboxylic acid, 1,2-H 2 BDC = 1,2-benzenedicarboxylic acid, H 2 ADB = 2,2'-azodibenzoic acid). Their structures were characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra, powder X-ray diffraction (PXRD) and thermogravimetric analyses (TGA). Compound 1 features a one-dimensional (1D) chain structure based on the rare heptanuclear [Zn 7 (µ 4 -O)(µ 3 -OAc) 2 (µ 2 -OAc) 8 ] units. Compound 2 exhibits a novel 2D bilayer structure built from the two parallel 2D (4,4) layers. Compound 3 holds a 2D structure in which the 1,2-BDC ligands work as lockers interlocking 1D [Zn(bpmb)] n chain. Compound 4 comprises a 3D framework constructed by 2D wrinkled [Zn 2 (ADB) 4 ] n networks and bpmb linkers with a six-connected pcu net. These results suggest that the motifs of the dicarboxylic ligands have significant effect on the final structures. These compounds exhibited relatively good photocatalytic activity towards the degradation of methylene blue (MB) in aqueous solution under a Xe lamp irradiation.

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Electronic and vibrational properties of a MOF-5 metal–organic framework: ZnO quantum dot behaviour

Cited by 495 publications

References 27 publications

Luminescent Properties of Metal–Organic Framework MOF-5: Relativistic Time-Dependent Density Functional Theory Investigations

Luminescent Properties of Metal–Organic Framework MOF-5: Relativistic Time-Dependent Density Functional Theory Investigations

Local Structure of CPO-27-Ni Metallorganic Framework upon Dehydration and Coordination of NO

Construction of Four Zn(II) Coordination Polymers Used as Catalysts for the Photodegradation of Organic Dyes in Water

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