College of Chemical Engineering, State Key Laboratory of Materials-oriented Chemical Engineering , Nanjing Tech University , Nanjing , 210009 , China.
State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing , 210093 , China.
Inorg Chem. 2019 Feb 18;58(4):2645-2651. doi: 10.1021/acs.inorgchem.8b03220. Epub 2019 Feb 7.
Polyoxovanadates (III) are important class of polyoxometalates in molecular magnetism field, and particularly the systems which contain vanadium(III) centers. To date, only very few highly reduced vanadium polynuclear complexes were reported, which remains a significant challenge to synthesize novel polyoxovanadates, owing to the characteristics of easily oxidized vanadium(III). Herein, two unprecedented petaloid chiral octanuclear polyoxovanadates, l- and d-HN(CH)(HO)(Vμ-OH)(SO)·2HO (L-, D-V), have been successfully obtained by solvothermal method without any chiral auxiliary. Both L- and D-V compounds contain the motif eight-membered ring (Vμ-O)(SO) constituted of three different chiral entangled loops with the V atoms as nodes. Bond valence calculation (BVC) analysis indicates that all the V ions existed in L, D-V are +3 value. The magnetic behavior of compounds indicated ferromagnetic coupling between vanadium(III) ions. To our knowledge, it is the first chiral highly reduced polyoxovanadates that exhibit excellent ferromagnetism.
多金属氧酸盐（III）在分子磁学领域中是一类重要的多酸，特别是含有钒（III）中心的体系。迄今为止，仅报道了极少数高度还原的钒多核配合物，由于钒（III）易氧化的特点，合成新型多金属氧酸盐仍然是一个重大挑战。在此，我们通过溶剂热法成功地获得了两个前所未有的花瓣状手性八核多金属氧酸盐 l- 和 d-HN(CH)(HO)(Vμ-OH)(SO)·2HO（L-，D-V），无需任何手性辅助剂。L-和 D-V 化合物均包含由三个不同手性缠绕环组成的 motif 八元环（Vμ-O）（SO），其中 V 原子为节点。键价计算（BVC）分析表明，L 和 D-V 中所有的 V 离子均为+3 价。化合物的磁性行为表明钒（III）离子之间存在铁磁耦合。据我们所知，这是首例具有优异铁磁性的手性高度还原多金属氧酸盐。
