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Calcium l-Lactate Frameworks as Naturally Degradable Carriers for Pesticides

Yang, Jingjing, Trickett, Christopher A., Alahmadi, Salman B., Alshammari, Ahmad S., Yaghi, Omar M.
Journal of the American Chemical Society 2017 v.139 no.24 pp. 8118-8121
acetates, air flow, calcium, coordination polymers, ethanol, fumigants, hydrolysis, ions, lactic acid, liquids, moieties, pesticides, porosity
Two porous, chiral metal–organic frameworks (MOFs), Ca₁₄(l-lactate)₂₀(acetate)₈(C₂H₅OH)(H₂O) (MOF-1201) and Ca₆(l-lactate)₃(acetate)₉(H₂O) (MOF-1203), are constructed from Ca²⁺ ions and l-lactate [CH₃CH(OH)COO–], where Ca²⁺ ions are bridged by the carboxylate and hydroxyl groups of lactate and the carboxylate group of acetate to give a three-dimensional arrangement of Ca(−COO, −OH) polyhedra supporting one-dimensional pores with apertures and internal diameters of 7.8 and 9.6 Å (MOF-1201) and 4.6 and 5.6 Å (MOF-1203), respectively. These MOFs represent the first examples of extended porous structures based on Ca²⁺ and lactate. They show permanent porosity of 430 and 160 m² g–¹, respectively, and can encapsulate an agriculturally important fumigant, cis-1,3-dichloropropene. MOF-1201 shows a 100 times lower release rate compared with liquid cis-1,3-dichloropropene under the same test conditions (25 °C, air flow rate of 1 cm³ min–¹). The hydrolysis of MOF-1201 in water makes it the first example of a degradable porous solid carrier for such fumigants.