[Chemical structure characteristics of organic carbon in saline soil aggregates under straw returning condition].

We examined the regularity of distribution and chemical structure characteristics of organic carbon in soda alkaline fluvo-aquic soil aggregates after straw returning. We set up six different straw returning treatments in 2020, including 0 (CK), 2100 (ST), 4200 (ST), 6300 (ST), 8400 (ST) and 10500 kg·hm(full straw returning, ST). We measured organic carbon (OC) content and infrared spectroscopy characteristics of aggregates and internal different components through physical fractionation method and infrared spectroscopy technology.

A POM-based copper-coordination polymer crystal material for phenolic compound degradation by immobilizing horseradish peroxidase.

A new polyoxometalate (POM)-based organic-inorganic hybrid Cu-coordination polymer, namely {((Cu(bipy))(-PhPO)Cu(bipy))H(PCuWO)·3HO} (denoted as compound 1, bipy = 2,2'-bipyridine, PhPO = phenylphosphonate), was self-assembled hydrothermally. Single-crystal X-ray diffraction (SC-XRD) analysis shows that two unique types of 1D chains are present in compound 1, Cu(II)-organophosphine and organonitrogen complex cation ([((Cu(bipy))(-PhPO)Cu(bipy))]) chains and Cu-monosubstituted Keggin-type polyoxoanion ([PCuWO]) chains, forming a hetero-POM. Crystalline compound 1 as a new enzyme immobilization support exhibited a high horseradish peroxidase (HRP) loading capacity (268 mg g).

A new hexamolybdate-based copper-2,2'-biimidazole coordination polymer serving as an acid catalyst and support for enzyme immobilization.

The hydrothermal reaction of (NH)[CoMoOH]·7HO (CoMo), CuCl·2HO and 2,2'-biimidazole (Hbiim) led to the formation of a new coordination polymer, namely poly[diaquabis(2,2'-biimidazole)hexa-μ-oxo-octa-μ-oxo-hexaoxodicopper(II)hexamolybdate(VI)], [CuMoO(CHN)(HO)] (Cu-MoO), at pH 2-3. It is obvious that in the formation of crystalline Cu-MoO, the original Anderson-type skeleton of heteropolymolybdate CoMo was broken and the new isopolyhexamolybdate MoO unit was assembled. In Cu-MoO, one MoO unit connects four [Cu(Hbiim)(HO)] ions in a pentacoordinate mode via four terminal O atoms, resulting in a tetra-supported structure, and each Cu ion is shared by two adjacent MoO units.

Three new Strandberg-type phenylphosphomolybdate supports for immobilizing horseradish peroxidase and their catalytic oxidation performances.

Three organic-inorganic hybrids containing Strandberg-type phenylphosphomolybdate anion [(C6H5PO3)2Mo5O15]4- with phenylphosphonate (PhP) centers, transition metal (TM) ions and 2,2'-biimidazole (H2biim) ligand, formulated as [(TM(H2biim)2)2(C6H5PO3)2Mo5O15]·H2O (TM = Co and Cu, abbreviated as Co-(PhP)2Mo5 and Cu-(PhP)2Mo5, respectively) and ([Ni(H2biim)3])2[(C6H5PO3)2Mo5O15]·2H2O (abbreviated as Ni-(PhP)2Mo5), were self-assembled by simple hydrothermal methods and were systematically characterized through single-crystal X-ray diffraction and other physicochemical and spectroscopic methods, which demonstrated that TM-H2biim complexes were firstly introduced into Strandberg-type organophosphomolybdate skeletons. Selecting the oxidation of cyclohexanol to cyclohexanone as a model reaction, using H2O2 as an oxidant, the catalytic oxidation activities of the Strandberg-type compounds were firstly evaluated. More importantly, these TM-(PhP)2Mo5 (TM = Co, Cu, Ni) compounds were employed to immobilize horseradish peroxidase (HRP), and showed high adsorption capacities for HRP.