173267-23-7

Upstream product

• 5870-38-2 diethyl 2,5-(dihydroxy)terephthalate 
• 77-78-1 dimethyl sulfate 
• 150-78-7 1,4-dimethoxybezene 
• 2674-34-2 1,4-dibromo-2,5-dimethoxybenzene 
• 64-17-5 ethanol 
• 21004-11-5 2,5-dimethoxyterephthalic acid 
• 74-88-4 methyl iodide 

Downstream Products

• 114503-42-3 2,5‐dimethoxyterephthalohydrazide 
• 143430-21-1 1,4-dimethoxy-2-nitrobenzene-3,6-dicarboxylic acid 
• 21004-11-5 2,5-dimethoxyterephthalic acid 
• 443643-19-4 1,4-bis(acylpyridin-2'-ylamidrazone)-2,5-dimethoxybenzene 
• 443643-12-7 1,4-bis(5'-(pyridin-2-yl)-1'H-1',2',4'-triazol-3'-yl)-2,5-dimethoxybenzene 
• 56486-55-6 2,5-dimethoxyterephthaloyl dichloride 
• 16877-79-5 diethyl 2,5-dihydroxy-1,4-cyclohexadiene-1,4-dicarboxylate 

Relevant academic research and scientific papers

Little change but great effect: Varying supra-molecular interactions in 2,5-dimethoxyterephthalic acid and 2,5-diethoxyterephthalic acid

The title terephthalic acid derivatives, namely 2,5-dimethoxyterephthalic acid, C10H10O6, (I), and 2,5- diethoxyterephthalic acid, C12H14O6, (II), exhibit nearly planar molecular structures, with maximum deviations from the leastsquares planes calculated for all non-H atoms of 0.0418 (6) and 0.0902 (10) A for (I) and (II), respectively. The molecules of both title compounds contain an inversion centre and thus the asymmetric unit of both crystal structures consists of only half a molecule. It is a remarkable fact that a comparatively small change in the substitution of the terephthalic acid [dimethoxy in (I) versus diethoxy in (II)] causes major differences in the dominating supramolecular interactions. While in (II) the packing structure is stabilized by typical intermolecular hydrogenbonded carboxylic acid dimer interactions, the carboxyl group in (I) forms an unusual intramolecular hydrogen bond with the O atom of the neighbouring methoxy group.

Electrochemical performance of graphene and copper oxide composites synthesized from a metal-organic framework (Cu-MOF)

A composite made from copper oxide (CuO) and exfoliated graphene (G) was synthesized by sintering a Cu-based metal-organic framework (Cu-MOF) embedded with exfoliated G. The G-embedded Cu-MOF was first synthesized by the self-assembly process of Cu(NO3)2·6H2O and DMTA (2,5-imethoxyterephthalatic acid) in the presence of exfoliated, few-layer G in the range of 2-5 μm. 5 wt% exfoliated G was incorporated into the MOF as an impurity. The X-Ray diffraction studies of the composite show that the characteristics of the few-layer G can be observed along with (hkl) lines of Cu-MOF. Upon heating, the Cu-MOF-G system decomposes to form a conductive composite consisting of sheet-like CuO and G sheets. Due to the ability of G to act as conductive additive, the CuO-G composite delivers improved electrochemical properties and stable cycling compared to pure CuO, the Cu-MOF or physically mixed Cu-MOF-G composites. The Royal Society of Chemistry 2013.

Experimental, Structural, and Computational Investigation of Mixed Metal-Organic Frameworks from Regioisomeric Ligands for Porosity Control

Porosity control and structural analysis of metal-organic frameworks (MOFs) can be achieved using regioisomeric ligand mixtures. While ortho-dimethoxy-functionalized MOFs yielded highly porous structures and para-dimethoxy-functionalized MOFs displayed almost nonporous properties in their N2 isotherms after evacuation, regioisomeric ligand-mixed MOFs showed variable N2 uptake amount and surface area depending on the ligand-mixing ratio. The quantity of N2 absorbed was tuned between 20 and 300 cm3/g by adjusting the ligand-mixing ratio. Both experimental analysis and computational modeling were performed to understand the porosity differences between ortho- A nd para-dimethoxy-functionalized MOFs. Detailed structural analysis using X-ray crystallographic data revealed significant differences in the coordination environments of DMOF-[2,3-(OMe)2] and DMOF-[2,5-(OMe)2] (DMOF = dabco MOF, dabco = 1,4-diazabicyclo[2.2.0]octane). The coordination bond between Zn2+ and carboxylate in the ortho-functionalized DMOF-[2,3-(OMe)2] was more rigid than that in the para-functionalized DMOF-[2,5-(OMe)2]. Quantum-chemical simulation also showed differences in the coordination environments of Zn secondary building unit surrounded by methoxy-functionalized ligands and pillar ligands. In addition, the binding energy differences between Zn2+ and regioisomeric ligands (ortho- A nd para-dimethoxy-functionalized benzene-1,4-dicarboxylates) explained the rigidity and porosity changes of the mixed MOFs upon evacuation and perfectly matched with experimental N2 adsorption and X-ray crystallography data.

Covalent Organic Frameworks toward Diverse Photocatalytic Aerobic Oxidations

Photoactive two-dimensional covalent organic frameworks (2D-COFs) have become promising heterogenous photocatalysts in visible-light-driven organic transformations. Herein, a visible-light-driven selective aerobic oxidation of various small organic molecules by using 2D-COFs as the photocatalyst was developed. In this protocol, due to the remarkable photocatalytic capability of hydrazone-based 2D-COF-1 on molecular oxygen activation, a wide range of amides, quinolones, heterocyclic compounds, and sulfoxides were obtained with high efficiency and excellent functional group tolerance under very mild reaction conditions. Furthermore, benefiting from the inherent advantage of heterogenous photocatalysis, prominent sustainability and easy photocatalyst recyclability, a drug molecule (modafinil) and an oxidized mustard gas simulant (2-chloroethyl ethyl sulfoxide) were selectively and easily obtained in scale-up reactions. Mechanistic investigations were conducted using radical quenching experiments and in situ ESR spectroscopy, all corroborating the proposed role of 2D-COF-1 in photocatalytic cycle.

Defect Engineering into Metal-Organic Frameworks for the Rapid and Sequential Installation of Functionalities

Postsynthetic treatments are well-known and important functionalization tools of metal-organic frameworks (MOFs). Herein, we have developed a practical and rapid postsynthetic ligand exchange (PSE) strategy using a defect-controlled MOF. An increase in the number of defects amounts to MOFs with enhanced rates of ligand exchange in a shorter time frame. An almost quantitative exchange was achieved by using the most defective MOFs. This PSE strategy is a straightforward method to introduce a functionality into MOFs including bulky or catalytically relevant moieties. Furthermore, some mechanistic insights into PSE were revealed, allowing for a sequential ligand exchange and the development of multifunctional MOFs with controlled ligand ratios.

Novel dirhodium coordination polymers: The impact of side chains on cyclopropanation

Seven novel dirhodium coordination polymers (Rh2-Ln) (n = 1-7) are prepared by employing bitopic ligands to connect dirhodium nodes. The formation of the framework is confirmed by attenuated total reflectance Fourier transform infrared (ATR-FTIR) and 1H → 13C cross polarization magic angle spinning nuclear magnetic resonance (CP MAS NMR) spectroscopy. Defect sites resulting from incomplete ligand substitution are revealed by 19F MAS NMR. The random stacking behavior of the frameworks in the obtained solid is analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The Rh2/O interaction in neighboring layers is investigated by diffuse reflectance ultra-violet visible light (DR-UV-vis) spectroscopy and X-ray photoelectron spectroscopy (XPS). This interaction is relevant to understand the catalytic behavior of various Rh2-Ln catalysts in the cyclopropanation of styrene with ethyl diazoacetate (EDA). In this context, the structure-reactivity relationship is discussed by taking into consideration both interlayer Rh2/O interactions and steric effects of side chains.

Flexibility in metal-organic frameworks derived from positional and electronic effects of functional groups

The position of identical functional groups and the subsequent electron density of structural benzene rings in a zinc-based metal-organic framework (MOF) have been controlled to reveal flexibility (or breathing behavior) differences. Both ortho- and para-positioned bi-functional benzene-1,4-dicarboxylic acid (BDC) ligands were synthesized with amino-, chloro-, methoxy-, and nitro groups. Additionally, two tri-functionalized, dimethoxy-amino and dimethoxy-nitro BDCs were prepared. All bi- and tri-functionalized BDCs were successfully incorporated into DABCO MOFs (DMOFs), except two diamino BDCs which were insoluble and thermally unstable. Among the eight bi-/tri-functionalized DMOFs, only para-dimethoxy exhibited flexibility in its framework after evacuation in preparation for N2 isotherm measurement. Since the dimethoxy combination has the most electron-rich environment in the benzene ring of the BDC in this series, this indicates that electron density plays a role in the flexibility changes of identically bi-functionalized DMOFs. However, the electron density alone could not fully explain the flexibility changes suggesting that the position of the functional groups is also important. These findings have been corroborated through the synthesis of two tri-functionalized DMOFs with identical functional group locations but opposite electronic environments.

Covalent organic frameworks as pH responsive signaling scaffolds

A β-ketoenamine based covalent organic framework, COF-JLU4, was synthesized by condensation of 2,5-dimethoxyterephthalohydrazide with triformylphloroglucinol under solvothermal conditions. This COF has strong crystallinity, good porosity, photoluminescence properties and wettability for water. It can serve as the first COF-based fluorescent pH sensor in aqueous solutions.

Synthesis, spectroscopic and electrochemical properties of mononuclear and dinuclear bis(bipy)ruthenium(II) complexes containing dimethoxyphenyl(pyridin-2-yl)-1,2,4-triazole ligands

The ligands HL1 and H2L2 and the complexes [Ru(bipy)2L1]PF6·2H2O 1, [(Ru(bipy)2)2L2](PF6)2·7H 2O 2, { where HL1 = 3-(2′,5′-dimethoxyphenyl)-5-(pyridin-2″-yl)-1 H-1,2,4-triazole, H2L2 = 1,4-bis(5′-(pyridin-2″-yl)- 1′H-1′,2′,4′-triazol-3′-yl)-2,5-dimethoxybenzene and bipy = 2,2′-bipyridyl}, have been prepared and characterised, by NMR, UV-vis and emission spectroscopies and by electrochemical measurements. X-Ray crystal structures of ligands HL1, H2L2 and of the complex 1 are also reported. The dinuclear complex (2) exhibits a weak electronic interaction between the metal centres, which is modulated by the protonation state of the 1,2,4-triazole rings. The extent of the metal-metal interaction in these systems is compared with that observed in other pyridyl-1,2,4-triazole based dinuclear compounds of differing metal-metal distances.