Highly tunable metal–organic frameworks with open metal centers

Choi, Eun‐Young; Wray, Curtis A.; Hu, Chunhua; Choe, Wonyoung

doi:10.1039/b819707p

“…Structural analysis revealed that the interlayer distance,w hich is measured from the apically bound atom at the Zn 2 (O 2 C)-SBU to the apically bound atom at the metalated porphyrin center of the next layer, had expanded from 2.82 , observed for a2 Dp orphyrin-based framework without fullerene linkers, [37] to 15.4 i n1 containing BPCF linkers,w hich is in line with the length of the pyridyl arms calculated from the single-crystal structure of BPCF (Figures 1a nd S2;m ore details are given in the Supporting Information). Coordinative immobilization of both linkers inside the rigid donoracceptor framework 1 was also confirmed based on acombination of 13 CC P-MAS and 1 HNMR spectroscopy and mass spectrometry (Figure 2).…”

mentioning

confidence: 99%

“…As previously shown, reactions of tetrakis(4-carboxyphenyl)porphyrin (H 4 TCPP) linkers with metal salts (in the absence of BPCF) led to the formation of two-dimensional planar Zn 2 (ZnTCPP) layers,i nw hich the porphyrin-containing donors were connected through Zn 2 (O 2 C-) secondary building units (SBUs). [37] Figure S3 shows that the solvent molecules occupy the apical positions of the Zn 2 (O 2 C-) 4 SBUsand could be replaced by different linkers which connect two adjacent Zn 2 (ZnTCPP) layers ( Figure S4). Thus,Zn 2+ ions in Zn 2 (O 2 C-) 4 could be used as anchor points for arrangement of the fullerene-based acceptors by coordinative immobilization between the layers.T op repare such af ullerene-porphyrin crystalline hybrid framework, H 4 TCPP and BPCF were heated in the presence of zinc nitrate at 80 8 8Cf or 16 h, which resulted in formation of [Zn 2 (ZnTCPP)(BPCF) 0.23 -(DEF) 0.77 ]·2(EtOH)·0.2H 2 O( 1, Scheme 1; the synthetic details can be found in the Supporting Information).…”

mentioning

confidence: 99%

Fulleretic Well‐Defined Scaffolds: Donor–Fullerene Alignment Through Metal Coordination and Its Effect on Photophysics

Williams

¹

,

Dolgopolova

²

,

Godfrey

³

et al. 2016

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Herein, we report the first example of ac rystalline metal-donor-fullerene framework, in which control of the donor-fullerene mutual orientation was achieved through chemical bond formation, in particular,bymetal coordination. The 13 Cc ross-polarization magic-angle spinning NMR spectroscopy, X-rayd iffraction, and time-resolved fluorescence spectroscopyw ere performed for comprehensive structural analysis and energy-transfer (ET) studies of the fulleretic donor-acceptor scaffold. Furthermore,i nc ombination with photoluminescence measurements,t he theoretical calculations of the spectral overlap function, Fçrster radius,e xcitation energies,a nd band structure were employed to elucidate the photophysical and ET processes in the prepared fulleretic material. We envision that the well-defined fulleretic donoracceptor materials could contribute not only to the basic science of fullerene chemistry but would also be used towards effective development of organic photovoltaics and molecular electronics.The success of fullerenes and their derivatives in engineering organic photovoltaics and molecular electronics is mainly owed to their electron-accepting properties and ultrafast electron/energy transfer. [1,2] As previously demonstrated, fullerene(acceptor)-donor alignment could significantly affect excitonic device performance.F or instance,t he arrangement of the donor fullerene is crucial for efficient energy/charge transfer, because of possible effects on the distance of exciton diffusion, p-p stacking, or Fçrster radius (resonance energy transfer). As ar esult, formation of fullerene stacks led to an enhancement of solar cell efficiency,in contrast to non-stacking fullerene derivatives. [3] There are few known reports of spatial organization of graphitic crystalline materials through the covalent linkage of fullerene derivatives. [4][5][6][7][8] Moreover,the known approaches for fulleretic material organization are mainly based on immobilization of the fullerenes inside porous matrices possessing alarge aperture. [9][10][11] There are very few reports of crystalline fullerene-metal-coordinated extended structures. [12][13][14][15] Furthermore,n one of these studies explore the concept demonstrated herein, which tackles the development of an ovel crystalline metal-donor-acceptor framework, in which control of the mutual orientation of the donor and fullerenebased acceptor was achieved through chemical bond formation, that is,m etal coordination. Despite the tremendous interest in self-assemblies (in particular,c oordination polymers such as covalent or metal-organic frameworks;COFs or MOFs) [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] and fullerene chemistry,t ot he best of our knowledge the prepared metal-organic fullerene-containing framework is the first example of ac rystalline hybridextended structure,inw hich control over mutual orientation of both donor and fullerene-based acceptor is achieved through metal coordination (Scheme 1). Scheme 1. As chematic representation of organizatio...

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“…Chemie center of the next layer, had expanded from 2.82 , observed for a2 Dp orphyrin-based framework without fullerene linkers, [37] to 15.4 i n1 containing BPCF linkers,w hich is in line with the length of the pyridyl arms calculated from the single-crystal structure of BPCF (Figures 1a nd S2;m ore details are given in the Supporting Information). Coordinative immobilization of both linkers inside the rigid donoracceptor framework 1 was also confirmed based on acombination of 13 CC P-MAS and 1 HNMR spectroscopy and mass spectrometry (Figure 2).…”

Section: Methodsmentioning

confidence: 65%

Fulleretic Well‐Defined Scaffolds: Donor–Fullerene Alignment Through Metal Coordination and Its Effect on Photophysics

Williams

¹

,

Dolgopolova

²

,

Godfrey

³

et al. 2016

View full text Add to dashboard Cite

Herein, we report the first example of ac rystalline metal-donor-fullerene framework, in which control of the donor-fullerene mutual orientation was achieved through chemical bond formation, in particular,bymetal coordination. The 13 Cc ross-polarization magic-angle spinning NMR spectroscopy, X-rayd iffraction, and time-resolved fluorescence spectroscopyw ere performed for comprehensive structural analysis and energy-transfer (ET) studies of the fulleretic donor-acceptor scaffold. Furthermore,i nc ombination with photoluminescence measurements,t he theoretical calculations of the spectral overlap function, Fçrster radius,e xcitation energies,a nd band structure were employed to elucidate the photophysical and ET processes in the prepared fulleretic material. We envision that the well-defined fulleretic donoracceptor materials could contribute not only to the basic science of fullerene chemistry but would also be used towards effective development of organic photovoltaics and molecular electronics.The success of fullerenes and their derivatives in engineering organic photovoltaics and molecular electronics is mainly owed to their electron-accepting properties and ultrafast electron/energy transfer. [1,2] As previously demonstrated, fullerene(acceptor)-donor alignment could significantly affect excitonic device performance.F or instance,t he arrangement of the donor fullerene is crucial for efficient energy/charge transfer, because of possible effects on the distance of exciton diffusion, p-p stacking, or Fçrster radius (resonance energy transfer). As ar esult, formation of fullerene stacks led to an enhancement of solar cell efficiency,in contrast to non-stacking fullerene derivatives. [3] There are few known reports of spatial organization of graphitic crystalline materials through the covalent linkage of fullerene derivatives. [4][5][6][7][8] Moreover,the known approaches for fulleretic material organization are mainly based on immobilization of the fullerenes inside porous matrices possessing alarge aperture. [9][10][11] There are very few reports of crystalline fullerene-metal-coordinated extended structures. [12][13][14][15] Furthermore,n one of these studies explore the concept demonstrated herein, which tackles the development of an ovel crystalline metal-donor-acceptor framework, in which control of the mutual orientation of the donor and fullerenebased acceptor was achieved through chemical bond formation, that is,m etal coordination. Despite the tremendous interest in self-assemblies (in particular,c oordination polymers such as covalent or metal-organic frameworks;COFs or MOFs) [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] and fullerene chemistry,t ot he best of our knowledge the prepared metal-organic fullerene-containing framework is the first example of ac rystalline hybridextended structure,inw hich control over mutual orientation of both donor and fullerene-based acceptor is achieved through metal coordination (Scheme 1). Scheme 1. As chematic representation of organizatio...

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“…As shown in Fig. 2, the diffraction pattern of [1] displayed several distinctive intense peaks whose positions approximately agreed with the superposition of the peak positions of the simulated XRD pattern of [Zn 2 (ZnTCPP)] [26], which was determined using a single-crystal X-ray structure. Therefore, it is obvious that the overall framework and packing structures of [1] were similar to that of [Zn 2 (ZnTCPP)].…”

Section: Resultsmentioning

confidence: 83%

“…The distribution of pore diameter, estimated using the Horvath-Kawazoe (HK) method, suggested that [1] has pores of approximately 4.7 Å in size similar to [Zn 2 (ZnTCPP)] (ca. 4.4 Å) of which value was estimated from the single crystal X-ray structures [26][27]. These results clearly indicated that [1] has a porous framework structure and sufficient micropores to permit N 2 gas adsorption.…”

Section: Resultsmentioning

confidence: 95%