Facile microwave synthesis, structural diversity and herbicidal activity of six novel alkaline-earth metal complexes (AECs) based on skeletal isomerization chlorophenoxyacetic acids

摘要: Six novel AECs of [Sr(o-CPA)2(H2O)4]·(o-CPA) 1, [Ba(o-CPA)2(H2O)]·H2O 2, [Sr(m-CPA)2(H2O)4]·(m-CPA) 3, [Ba(m-CPA)2(H2O)4]2·2(m-CPA)·H2O 4, [Sr(p-CPA)2(H2O)] 5 and [Ba(p-CPA)2(H2O)] 6 (o-CPA = 2-chlorophenoxyacetic acid, m-CPA 3-chlorophenoxyacetic acid p-CPA 4-chlorophenoxyacetic acid) were synthesized by a facile microwave-assistant reaction. The solid-state structures well established X-ray crystallography routine analyses Fourier transform infrared, elemental analysis, field emission scanning electron microscope (FESEM) thermogravimetric analysis. structure data reveal that complexes 3 4 are one-dimensional chains with zigzag arrangement, while (4, 4) rhomboid two-dimensional grid structures. It is noticed the carboxyl group in these displays multiple coordination modes μ2-η1:η1 (1, 6), μ3-η1:η2 4), μ2-η1:η2 (2), μ3-η2:η2 (5 6). Interestingly, oxygen atoms flexible –OCH2– phenoxy groups take part behavior metal centers through rotation C–O C–C bonds 6, only can be found 4. FESEM images indicate surface appearances totally different from ligands after coordination. All evaluated for activity as plant-growth inhibitors against Amaranth (Amaranthus spp.) barnyard grass. Compared ligands, exhibited better response index (RI) values Shoot elongation Moreover, demonstrated higher inhibitory than 6. significant to develop new kind environmentally-friendly herbicide based on kinds their low toxicity high efficiency.