ABSTRACT
Enantioselective synthesis of homochiral rare earth clusters is still a great challenge. In this work, we developed an efficient "cluster to cluster" approach, that is, a pair of enantiomerical R/S-{Nd8Fe3}-oxo clusters were successfully obtained from the presynthesized racemic {Nd9Fe2}-oxo cluster. R/S-hydrobenzoin ligands trigger the transformation of the pristine clusters by an SN2-like mechanism. Compared to the pristine cluster with an achiral core, the new cluster exhibits hierarchical chirality, from ligand chirality to interface chirality, then to helix chirality, and finally to supramolecular double helix chirality. The spectral experiments monitored the transformation and confirmed distinctly structure-related optical activity. The enantiomeric pure cluster also exhibits a potential asymmetric catalytic activity.
ABSTRACT
In this paper, we report the successful assembly of achiral {Ln6M} ([Ln6M(µ3-OH)8(acac)12(CH3O)x(CH3OH)y], Ln = La, M = Mn, Co, Fe) and chiral {Nd9Fe2} ([Nd9Fe2(µ4-O)(µ3-OH)14(acac)16(NO3)(CH3OH)2(H2O)3]) rare earth clusters using achiral rigid ligands and a transition metal doping strategy. {Ln6M} can be viewed as the fusion of two {Ln3M} tetrahedrons by sharing vertices. {Nd9Fe2} results from the fusion of four {Ln3M} tetrahedrons by vertice and edge sharing. The substitution of Ln with transition metal leads to changes in the coordination pattern around neighboring Ln, which triggers the switch of metal center chirality. This study demonstrates the potentiality of utilizing transition metal doping and rigid ligand to control the chirality of rare earth clusters. In addition, the photocatalytic CO2 activity of these transition metal-doped rare earth clusters has been studied.
ABSTRACT
Growing evidences have confirmed the effect of Sacubitril/Valsartan (SV) on antihypertension and cardiac protection in general population. However, there was no prospective study about the effect and safety of SV on resistant hypertension and myocardial work in hemodialysis patients. In this single-center, prospective, before-after study, enrolled patients were endured with resistant hypertension for more than 6 months. Participants were initially instructed to take SV 50 mg twice daily, and the dosage was gradually increased up to 100 mg twice daily. The primary outcomes were blood pressure (BP) control, N-terminal pro-B-type natriuretic peptide (NT-proBNP), myocardial work (MW), fatigue and life quality. In addition, the adverse events were also recorded in this cohort. A total of 18 patients (34-64 years old) was finally enrolled and completed in this study. The SV-based regimen provided significantly mean sitting systolic BP (msSBP) and mean sitting diastolic BP (msDBP) reductions from baseline (-20.7/-8.3 mm Hg), respectively. The cardiac remodeling parameters were partially improved. Compared to the baseline, NT-proBNP was significantly reduced at week 4 (8119.50 [3710.75, 29300] pg/ml to 7216.50 [4124.75, 17455.00] pg/ml, p = .046), which was much lower at week 12 (3130.50 [2244.50, 9565.70] pg/ml, p = .037). Global MW index was higher at week 12 compared to the baseline (p = .026). MW efficiency was also improved accordingly compared to the baseline, even though the statistical difference was not significant (p = .226). Life quality and fatigue were improved at week 12 compared to the baseline (all p = .000). There was no serious adverse events were observed. SV safely and effectively controlled resistant hypertension and improved MW as well as life quality in hemodialysis patients.
