Carborane Bis-pyridylalcohols as Linkers for Coordination Polymers: Synthesis, Crystal Structures, and Guest-Framework Dependent Mechanical Properties

Abstract

We report the synthesis and characterization of six novel coordination polymers (CPs) based on M(II) (M: Zn and Co), di-, tri-and tetracarboxylate linkers and two novel bispyridylalcohol 1,7-bis{(piridin-n'-yl)methanol}-1,7-dicarba-closo-dodecaboranes (n' = 3, L1; n' = 4, L2) ligands. The polycarboxylates are terephthalic acid (H 2 BDC), 1,3,5-benzenetricarboxylic acid (H 3 BTB) and 1,2,4,5-tetrakis(4-carboxyphenyl)benzene (H 4 TCPB). Structural description of CPs reveals the flexibility of the carborane ligands and their ability to construct extended structures.The CP containing Co(II), BTB and L2 behaves as a crystalline sponge for a variety of guests, showing a higher affinity for aromatic guest molecules. Single-crystal nanoindentation experiments indicate that a high number of specific interactions between the guests and the CP framework results in a high elastic modulus and hardness values.

A Highly Water-Stable meta-Carborane-Based Copper Metal–Organic Framework for Efficient High-Temperature Butanol Separation

“…[31][32][33][34][35][36][37][38][39][40][41] To improve the hydrolytic and thermal stability, as well as the hydrophobicity of MOFs, ligands based on carboranes can be introduced within their structures. [42][43][44] Icosahedral boranes and carboranes ([B12H12] 2and 1,n-C2B10H12 (n = 2, 7 or 12) are a class of commercially available and exceptionally stable 3D-aromatic boron-rich clusters that possess material-favorable properties such as thermal and chemical stability and high hydrophobicity. 3,[45][46][47][48] The neutral carboranes are remarkably robust boron clusters with two carbon atoms and possess 26 electrons for 12 vertices.…”

“…44 This report was followed by a series of m-carborane based Co and Zn coordination polymers with high hydrolytic stabilities. [42][43] Inspired by the intriguing properties of carborane based MOFs, herein, we report a novel Cu2paddlewheel based MOF with formula [Cu2(mCB-L)2(DABCO)0.5(H2O)] (mCB-MOF-1; mCB-L:…”

Microsphere Assemblies via Phosphonate Monoester Coordination Chemistry

“…The corresponding E values for CALS‐1–4 are 11.76±2.54, 11.13±1.21, 12.09±1.85 and 9.56±2.86 GPa, respectively. These values are among the highest seen for porous MOFs, although a series of MIL‐140 MOFs show Young's modulus values larger than 100 . The values of E and H are on par with values seen for some 3D dense materials, including perovskites .…”

“…This has largely been attributed to the anisotropy associated with MOFs and the exposure of different crystal facets to the indenter tip. The corresponding Ev alues for CALS-1-4 are 11.76 AE 2.54, 11.13 AE 1.21, 12.09 AE 1.85 and 9.56 AE 2.86 GPa, respectively.T hese valuesa re among the highest seen for porous MOFs, [34][35][36] although as eries of MIL-140 MOFs showY oung's modulus values largert han 100. The corresponding Ev alues for CALS-1-4 are 11.76 AE 2.54, 11.13 AE 1.21, 12.09 AE 1.85 and 9.56 AE 2.86 GPa, respectively.T hese valuesa re among the highest seen for porous MOFs, [34][35][36] although as eries of MIL-140 MOFs showY oung's modulus values largert han 100.…”

A Reversible Phase Transition of 2D Coordination Layers by B–H∙∙∙Cu(II) Interactions in a Coordination Polymer

“…Dicarboxylic and tricarboxylic derivatives of the smaller carborane closo -1,10-C 2 B 8 H 10 were also incorporated into porous CPs [38,45]. We have recently designed flexible carborane-based ligands for dynamic MOFs ( VI and VII in Scheme 1) [46,47]. In addition to water stability [47], the spherical shape of the carborane moiety in these flexible linkers seems to have a noticeable influence in the dynamic behavior of the MOFs.…”