Thermal Expansion Properties and Mechanochemical Synthesis of Stoichiometric Cocrystals Containing Tetrabromobenzene as a Hydrogen‐ and Halogen‐Bond Donor
Title: Thermal Expansion Properties and Mechanochemical Synthesis of Stoichiometric Cocrystals Containing Tetrabromobenzene as a Hydrogen‐ and Halogen‐Bond Donor
Abstract The solution and mechanochemical synthesis of two cocrystals that differ in the stoichiometric ratio of the components (stoichiometric cocrystals) is reported. The components in the stoichiometric cocrystals interact through hydrogen or hydrogen/halogen bonds and differ in π‐stacking arrangements. The difference in structure and noncovalent interactions affords dramatically different thermal expansion behaviors in the two cocrystals. At certain molar ratios, the cocrystals are obtained concomitantly; however, by varying the ratios, a single stoichiometric cocrystal is achieved using mechanochemistry. more »« less
Yelgaonkar, Shweta P.; Kiani, Daniyal; Baltrusaitis, Jonas; MacGillivray, Leonard R.
(, Chemical Communications)
null
(Ed.)
Salt cocrystals with components that assemble by hydrogen bonds and aromatic anion–molecule stacks (π − –π stacks) are reported. U-shaped bipyridines and an isocoumarin carboxylic acid self-assemble to form 5-, 6-, and 10-component aggregates with components in double and quadruple face-to-face stacks. DFT calculations support the π − –π stacks to help stabilize the salt cocrystals.
Abstract Climate and land management affect nutrient cycling in grassland ecosystems. We aimed to understand whether temperate and tropical grasslands differ in terms of soil organic carbon (SOC), nitrogen (N), and phosphorus (P) concentrations, and their C:N:P stoichiometric ratios in grazed and ungrazed natural grasslands and pastures. For this, we used a meta-analysis approach (1296 records, 241 papers), and regression models to explain the observed patterns in terms of mean annual precipitation (MAP), mean annual temperature (MAT), altitude, and latitude. SOC, N, and P concentrations were higher in temperate regions than in tropical ones, and they negatively correlated with MAT and MAP. The grassland type effect was more significant for tropical regions. In tropical regions, soil C:N ratios were higher in ungrazed than in grazed pastures, and soil N:P ratios in ungrazed sites were higher in pastures than in natural grasslands. Grazing increases soil N and SOC for natural grasslands in temperate regions. Our findings suggest that soil stoichiometric C:N:P stoichiometric signatures in grasslands differed between tropical and temperate regions on a global scale. P is a key element in regulation and restriction on soil C and N cycling in tropical regions but less in the temperate ones. Our findings suggest the direction of effects of grazing or grassland type on C:N:P stoichiometric signature. Since imbalances in soil stoichiometric ratios may have implications for ecosystem functioning, the assessment of these patterns could serve as a valuable tool for management and conservation of grasslands and pastures in both tropical and temperate regions.
Juneja, Navkiran; Shapiro, Nicole M.; Unruh, Daniel K.; Bosch, Eric; Groeneman, Ryan H.; Hutchins, Kristin M.
(, Angewandte Chemie International Edition)
Abstract Control over thermal expansion (TE) behaviors in solid materials is often accomplished by modifying the molecules or intermolecular interactions within the solid. Here, we use a mixed cocrystal approach and incorporate molecules with similar chemical structures, but distinct functionalities. Development of mixed cocrystals is at a nascent stage, and here we describe the first mixed cocrystals sustained by one‐dimensional halogen bonds. Within each mixed cocrystal, the halogen‐bond donor is fixed, while the halogen‐bond acceptor site contains two molecules in a variable ratio. X‐ray diffraction demonstrates isostructurality across the series, and SEM‐EDS shows equal distribution of heavy atoms and similar atomic compositions across all mixed cocrystals. The acceptor molecules differ in their ability to undergo dynamic motion in the solid state. The synthetic equivalents of motion capable and incapable molecules were systematically varied to yield direct tunabililty in TE behavior.
Guadalupe_Vasquez‐Ríos , María; Campillo‐Alvarado, Gonzalo; Swenson, Dale_C; Höpfl, Herbert; MacGillivray, Leonard_R
(, Chemistry – A European Journal)
Abstract Cocrystallizations of diboronic acids [1,3‐benzenediboronic acid (1,3‐bdba), 1,4‐benzenediboronic acid (1,4‐bdba) and 4,4’‐biphenyldiboronic acid (4,4’‐bphdba)] and bipyridines [1,2‐bis(4‐pyridyl)ethylene (bpe) and 1,2‐bis(4‐pyridyl)ethane (bpeta)] generated the hydrogen‐bonded 1 : 2 cocrystals [(1,4‐bdba)(bpe)2] (1), [(1,4‐bdba)(bpeta)2] (2), [(1,3‐bdba)(bpe)2(H2O)2] (3) and [(1,3‐bdba)(bpeta)2(H2O)] (4), wherein 1,3‐bdba involved hydrated assemblies. The linear extended 4,4’‐bphdba exhibited the formation of 1 : 1 cocrystals [(4,4'‐bphdba)(bpe)] (5) and [(4,4'‐bphdba‐me)(bpeta)] (6). For 6, a hemiester was generated by an in‐situ linker transformation. Single‐crystal X‐ray diffraction revealed all structures to be sustained by B(O)−H⋅⋅⋅N, B(O)−H⋅⋅⋅O, Ow−H⋅⋅⋅O, Ow−H⋅⋅⋅N, C−H⋅⋅⋅O, C−H⋅⋅⋅N, π⋅⋅⋅π, and C−H⋅⋅⋅π interactions. The cocrystals comprise 1D, 2D, and 3D hydrogen‐bonded frameworks with components that display reactivities upon cocrystal formation and within the solids. In 1 and 3, the C=C bonds of the bpe molecules undergo a [2+2] photodimerization. UV radiation of each compound resulted in quantitative conversion of bpe into cyclobutane tpcb. The reactivity involving 1 occurred via 1D‐to‐2D single‐crystal‐to‐single‐crystal (SCSC) transformation. Our work supports the feasibility of the diboronic acids as formidable structural and reactivity building blocks for cocrystal construction.
Bosch, Eric; Bowling, Nathan P.
(, Acta Crystallographica Section C Structural Chemistry)
The rapid evaporation of 1:1 solutions of diethynylpyridines and N -halosuccinimides, that react together to form haloalkynes, led to the isolation of unreacted 1:1 cocrystals of the two components. The 1:1 cocrystal formed between 2,6-diethynylpyridine and N -iodosuccinimide (C 4 H 4 INO 2 ·C 9 H 5 N) contains an N -iodosuccinimide–pyridine I...N halogen bond and two terminal alkyne–succinimide carbonyl C—H...O hydrogen bonds. The three-dimensional extended structure features interwoven double-stranded supramolecular polymers that are interconnected through halogen bonds. The cocrystal formed between 3,5-diethynylpyridine and N -iodosuccinimide (C 4 H 4 INO 2 ·C 9 H 5 N) also features an I...N halogen bond and two C—H...O hydrogen bonds. However, the components form essentially planar double-stranded one-dimensional zigzag supramolecular polymers. The cocrystal formed between 3,5-diethynylpyridine and N -bromosuccinimide (C 4 H 4 BrNO 2 ·C 9 H 5 N) is isomorphous to the cocrystal formed between 3,5-diethynylpyridine and N -iodosuccinimide, with a Br...N halogen bond instead of an I...N halogen bond.
Ding, Xiaodan, Crawford, Adam_W, Derrick, William_P, Unruh, Daniel_K, Groeneman, Ryan_H, and Hutchins, Kristin_M. Thermal Expansion Properties and Mechanochemical Synthesis of Stoichiometric Cocrystals Containing Tetrabromobenzene as a Hydrogen‐ and Halogen‐Bond Donor. Chemistry – A European Journal 27.66 Web. doi:10.1002/chem.202102833.
Ding, Xiaodan, Crawford, Adam_W, Derrick, William_P, Unruh, Daniel_K, Groeneman, Ryan_H, and Hutchins, Kristin_M.
"Thermal Expansion Properties and Mechanochemical Synthesis of Stoichiometric Cocrystals Containing Tetrabromobenzene as a Hydrogen‐ and Halogen‐Bond Donor". Chemistry – A European Journal 27 (66). Country unknown/Code not available: Wiley Blackwell (John Wiley & Sons). https://doi.org/10.1002/chem.202102833.https://par.nsf.gov/biblio/10303982.
@article{osti_10303982,
place = {Country unknown/Code not available},
title = {Thermal Expansion Properties and Mechanochemical Synthesis of Stoichiometric Cocrystals Containing Tetrabromobenzene as a Hydrogen‐ and Halogen‐Bond Donor},
url = {https://par.nsf.gov/biblio/10303982},
DOI = {10.1002/chem.202102833},
abstractNote = {Abstract The solution and mechanochemical synthesis of two cocrystals that differ in the stoichiometric ratio of the components (stoichiometric cocrystals) is reported. The components in the stoichiometric cocrystals interact through hydrogen or hydrogen/halogen bonds and differ in π‐stacking arrangements. The difference in structure and noncovalent interactions affords dramatically different thermal expansion behaviors in the two cocrystals. At certain molar ratios, the cocrystals are obtained concomitantly; however, by varying the ratios, a single stoichiometric cocrystal is achieved using mechanochemistry.},
journal = {Chemistry – A European Journal},
volume = {27},
number = {66},
publisher = {Wiley Blackwell (John Wiley & Sons)},
author = {Ding, Xiaodan and Crawford, Adam_W and Derrick, William_P and Unruh, Daniel_K and Groeneman, Ryan_H and Hutchins, Kristin_M},
}
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