Giant Cavity Macrocycle: Synthesis, Structure, and Its Complexation with Pagoda[5]arene.

A novel stretched hexagon structure naphthalene diimides-extended-pillar[6]arene 1 with a giant cavity size of 18.769 Å in width and 17.109 Å in height is reported. 1 exhibits highly selective binding of pagoda[5]arene compared to pillar[5]arene and prism[5]arene. Size matching and charge transfer interactions play a key role in the formation of the ring-in-ring stable complex.

Clinical Features and Differences of Miller Fisher Syndrome in Southern China: Retrospective Analysis of 72 Patients in 13 Provinces of Southern China.

BACKGROUND AND PURPOSE: We aimed to determine the clinical features of Miller Fisher syndrome (MFS) in southern China and compare them with those presenting in other countries. METHODS: We collected the medical records of patients diagnosed with MFS during 2013-2016. We analyzed the age, sex, onset season, precursor events, clinical symptoms and signs, findings of nerve conduction studies (NCS), cerebrospinal fluid (CSF), therapeutic remedies, nadir time, and length of hospital stay of patients with MFS in southern China. We concurrently compared the differences between urban and rural areas and between patients with incomplete ophthalmoplegia (IO) and complete ophthalmoplegia (CO). RESULTS: The study enrolled 72 patients: 36 from rural areas and 36 from urban areas, and 50 males and 22 females. The mean age at onset was 47.72 years, and 30 (41.7%) and 21 (29.2%) patients developed MFS in spring and winter, respectively. The typical triad of ophthalmoplegia, ataxia, and areflexia was observed in 50 (69.4%) patients. A history of upper respiratory tract infection 1 week before onset was found in 52.8% of the patients, while 5.6% experienced gastrointestinal infections and 48 (73.8%) exhibited albuminocytological dissociation in the CSF study. Only 26 (36.1%) patients presented abnormalities in NCS. Moreover, restricted outward eyeball movement presented in 83.5% of the patients with classic MFS and acute ophthalmoplegia, and bilateral symmetrical ophthalmoplegia presented in 64.2%. With the exception of the higher proportion of NCS abnormalities in urban areas (47.2% vs. 25.0%), urban and rural differences were insignificant regarding sex ratio, age at onset, high-incidence season, precursor events, disease characteristics, and albuminocytological dissociation in the CSF. Furthermore, patients with CO were older than those with IO (64.53±7.69 vs. 43.19±14.40 years [mean±standard deviation], p<0.001). CONCLUSIONS: The patients with MFS were mostly male and middle-aged, and most presented in winter and (especially) spring. More than half of the patients had clear precursor events, most of which were classic MFS with the typical triad. More than 70% of the patients presented albuminocytological dissociation in the CSF. NCS abnormalities were uncommon in MFS. The age at onset was lower in patients with IO than in patients with CO; bilateral symmetrical extraocular muscle paralysis was the most common symptom, and the external rectus was the most frequently involved muscle.

SS-31 alleviated nociceptive responses and restored mitochondrial function in a headache mouse model via Sirt3/Pgc-1α positive feedback loop.

Migraine is the second highest cause of disability worldwide, bringing a huge socioeconomic burden. Improving mitochondrial function has promise as an effective treatment strategy for migraine. Szeto-Schiller peptide (SS-31) is a new mitochondria-targeted tetrapeptide molecule that has been shown to suppress the progression of diseases by restoring mitochondrial function, including renal disease, cardiac disease, and neurodegenerative disease. However, whether SS-31 has a therapeutic effect on migraine remains unclear. The aim of this study is to clarify the treatment of SS-31 for headache and its potential mechanisms. Here we used a mouse model induced by repeated dural infusion of inflammatory soup (IS), and examined roles of Sirt3/Pgc-1α positive feedback loop in headache pathogenesis and mitochondrial function. Our results showed that repeated IS infusion impaired mitochondrial function, mitochondrial ultrastructure and mitochondrial homeostasis in the trigeminal nucleus caudalis (TNC). These IS-induced damages in TNC were reversed by SS-31. In addition, IS-induced nociceptive responses were simultaneously alleviated. The effects of SS-31 on mitochondrial function and mitochondrial homeostasis (mainly mitochondrial biogenesis) were attenuated partially by the inhibitor of Sirt3/Pgc-1α. Overexpression of Sirt3/Pgc-1α increased the protein level of each other. These results indicated that SS-31 alleviated nociceptive responses and restored mitochondrial function in an IS-induced headache mouse model via Sirt3/Pgc-1α positive feedback loop. SS-31 has the potential to be an effective drug candidate for headache treatment.

MicroRNA-23a-3p Is Upregulated in Plasma Exosomes of Bulbar-onset ALS Patients and Targets ERBB4.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease related to the progressive death of motor neurons. Understanding the pathogenesis of ALS continues to provide considerable challenges. Bulbar-onset ALS involves faster functional loss and shorter survival time than spinal cord-onset ALS. However, debate is ongoing regarding typical plasma miRNA changes in ALS patients with bulbar onset. Exosomal miRNAs have not yet been described as a tool for bulbar-onset ALS diagnosis or prognosis prediction. In this study, candidate exosomal miRNAs were identified by small RNA sequencing using samples from patients with bulbar-onset ALS and healthy controls. Potential pathogenic mechanisms were identified through enrichment analysis of target genes for differential miRNAs. Expression of miR-16-5p, miR-23a-3p, miR-22-3p, and miR-93-5p was significantly up-regulated in plasma exosomes from bulbar-onset ALS patients compared with healthy control subjects. Among them, miR-16-5p and miR-23a-3p were significantly lower in spinal-onset ALS patients than those with bulbar-onset. Furthermore, up-regulation of miR-23a-3p in motor neuron-like NSC-34 cells promoted apoptosis and inhibited cell viability. This miRNA was found to directly target ERBB4 and regulate the AKT/GSK3ß pathway. Collectively, the above miRNAs and their targets are related to the development of bulbar-onset ALS. Our research indicates that miR-23a-3p might have an effect on motor neuron loss observed in bulbar-onset ALS and may be a novel target for the therapy of ALS in the future.

Water soluble macrocyclic host for recognition of N-methylquinolinium salts in water.

In this paper, we reported the synthesis of water soluble macrocyclic arenes 1 containing anionic carboxylate groups. It was found that host 1 could form a 1 : 1 complex with N-methylquinolinium salts in water. Moreover, the complexation and decomplexation of the complexes between host and the guests could be achieved by changing the pH of the solution, and the process could also be observed by naked eye.

Evaluating the Catalytic Activities of PNCNP Pincer Group 10 Metal Hydride Complexes: Pd-Catalyzed Reduction of CO2 to the Formic Acid Level with NH3·BH3 and NaBH4 under Ambient Conditions.

In order to develop efficient protocols for CO2 reduction with less expensive and more convenient hydrogen sources, the catalytic reactivities of group 10 metal hydride complexes supported by a PNCNP pincer ligand, [2,6-(tBu2PNH)2C6H3]MH (M = Ni, 1a; Pd, 1b; Pt, 1c), against the hydroboration of CO2 with NH3·BH3 and NaBH4 have been explored. Both 1a and 1b readily react with CO2 at room temperature to form the corresponding formato complexes, [2,6-(tBu2PNH)2C6H3]MOC(O)H (M = Ni, 2a; Pd, 2b), in nearly quantitative yields. Treatment of NH3·BH3 with CO2 (1 atm) in 1,4-dioxane or THF at room temperature in the presence of 0.05-1.0 mol % of 1b followed by hydrolysis of the resulting mixtures produces formic acid in 105-186% yields, and initial turnover frequencies of up to 2000 h-1 are observed. In the presence of 1.0 mol % of 1b, NaBH4 reacts with CO2 (1 atm) in THF at room temperature to form NaB[OC(O)H]4 (3) in 87% isolated yield. In situ NMR spectroscopy indicates that the reactions proceed through the insertion of the C═O bond in CO2 into the Pd-H bond in 1b to form 2b, which sequentially reacts with the hydrides in NH3·BH3 or NaBH4 to produce boron formato species and regenerate 1b. This work represents one of the rare examples of catalytic transfer hydrogenation of CO2 with NH3·BH3 to the formic acid level under very mild conditions without any additives and also the first example of 4 equiv of CO2 uptake by NaBH4 in a reaction.

[Research advance on the pathogenesis of autosomal recessive spastic ataxia of Charlevoix-Saguenay].

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a rare and early-onset neurodegenerative disease caused by variants of the SACS gene which maps to chromosome 13q11 and encodes sacsin protein. Sacsin is highly expressed in large motor neurons, in particular cerebellar Purkinje cells. This article has provided a review for the structure and function of sacsin protein and the mechanisms underlying abnormalities of sacsin in ARSACS disease.

Downregulation of GABAARα1 Aggravates Comorbidity of Epilepsy and Migraine via the TLR4 Signaling Pathway.

Epilepsy and migraine are among the most prevalent neurological disorders. By being comorbid, the presence of one disorder increases the likelihood of the other. Although several similar clinical features of epilepsy and migraine have been observed as early as the 19th century, only in recent years have researchers engaged in finding a common pathogenic mechanism between them. In this study, the epilepsy-migraine comorbidity rat model was generated, and the pathophysiological basis of epilepsy-migraine comorbidity was examined. Male rats were divided into four groups: control, migraine, epilepsy, epilepsy-migraine comorbidity. After establishing the models, the amount of scratching and the pain threshold of the rats were observed. Western blot and immunofluorescence staining were used to detect the protein expression levels of TLR4 and GABAARα1 in the temporal cortex, hippocampus, trigeminal ganglion, and medullary dorsal horn. Subsequently, co-immunoprecipitation of GABAARα1 and TLR4 was performed. Then, the rats were divided into three groups: comorbidity, comorbidity + TAK-242, and comorbidity + muscimol. After drug intervention, the seizure latency, seizure level, amount of scratching, and pain threshold were observed. Western blot was used to detect the protein expression levels of TLR4 and GABAARα1 in the temporal cortex, hippocampus, trigeminal ganglion, and medullary dorsal horn. Our results demonstrate that the seizure attacks in comorbidity and epilepsy groups performed severely, and the comorbidity and migraine groups displayed a remarkable increase in the amount of head-scratching and a noticeable decrease in the facial mechanical withdrawal threshold. Further analysis revealed considerably increased Toll-like receptor 4 (TLR4), associated with reduced γ-aminobutyric acid type A receptor α1 (GABAARα1) and microglia enhanced in the epilepsy-migraine comorbidity rat. Additionally, co-immunoprecipitation proved GABAARα1 binding TLR4. Following muscimol to activate GABAARα1, seizure attacks and migraine-like behavior were rescued. GABAARα1 level increment was accompanied by the decline of TLR4, while TAK-242, the inhibitor of TLR4, only decreased TLR4 without affecting GABAARα1 expression. It also ameliorated the migraine-like behavior with no impact on seizure activity. We propose that GABAARα1 binding and negatively regulating TLR4 contribute to epilepsy-migraine comorbidity; TLR4 is a critical intermediate link in epilepsy-migraine comorbidity; immune-induced neuroinflammation in microglia may be involved in migraine and epilepsy-migraine comorbidity.

Noncatalyzed Reduction of Nitriles to Primary Amines with Ammonia Borane.

The preparation of primary amines from nitriles has been a subject of continuing interest, and many different methods have been reported for this process. We report in this paper an alternative method for transforming nitriles into primary amines. In this work, a wide range of nitriles were reduced to primary amines by 1.2 equiv of ammonia borane under thermal decomposition conditions without any catalyst and the corresponding primary amines were isolated in good to excellent yields. The reactions are environmentally benign with H2 and NH3 generated as byproducts. The reactions are also tolerant of many functional groups. Nitriles are likely reduced by the in situ-generated aminodiborane, the application of which in organic synthesis has never been reported before. By using our protocol, primary amines containing multifluorinated aromatic rings, which are greatly important in pharmaceutical synthesis and have rarely been prepared via catalytic processes, were successfully prepared.

Reactions and catalytic applications of a PNCNP pincer palladium hydride complex.

A palladium(II) hydride complex supported by a benzene-based PNCNP pincer ligand, [2,6-(tBu2PNH)2C6H3]PdH (1), has been synthesized via two different routes: the reaction of the corresponding chloride complex with LiAlH4 and the reaction of the corresponding nitrate complex with KOCH3. Complex 1 exhibits strong deprotonating ability and versatile catalytic activity. Acetamide can be readily deprotonated by complex 1 to form the corresponding acetamido complex, [2,6-(tBu2PNH)2C6H3]PdNHC(O)CH3, in high yield. Complex 1 is an active catalyst for both the dehydrogenation of methanol to formaldehyde under mild conditions and direct hydration of nitriles to primary amides. Particularly, the direct hydration of nitriles to primary amides catalysed by complex 1 represents the most efficient palladium catalytic system for this type of reaction. A wide range of nitriles have been successfully hydrated to primary amides with 100% selectivity and good to excellent isolated yields. The possible reaction mechanisms are discussed.

Adsorptive separation of para-xylene by nonporous adaptive crystals of phenanthrene[2]arene.

In this work, we developed a new method for the preparation of phenanthrene[2]arene on a large-scale. Meanwhile, the synthetic phenanthrene[2]arene has been successfully used as nonporous adaptive crystals for the separation of para-xylene (pX) from xylene isomers. The crystal structure revealed that one host molecule can adsorb one pX molecule to form the 1@pX complex, in which pX is located in the cavity of the host.

Coordination mode and stability of the tetrahydroborate ligand in group 10 metal pincer complexes.

The coordination mode of the BH4- ligand in transition metal tetrahydroborate complexes is mainly dominated by the nature of the metal centres. However, other factors can also play important roles sometimes. In order to rationalize the coordination modes and the stability of the BH4- ligand in group 10 metal tetrahydroborate pincer complexes, [2,6-(tBu2PO)2C6H3]Pt(η1-HBH3) and [C6H4-o-(NCH2PtBu2)2B]M(η2-H2BH2) (M = Ni, Pt) were prepared and characterized. A structural comparison of [2,6-(tBu2PCH2)2C6H3]Ni(BH4), [2,6-(tBu2PO)2C6H3]M(BH4) and [C6H4-o-(NCH2PtBu2)2B]M(BH4) (M = Ni, Pd, and Pt) indicates that the M-P bond length, the P-M-P bite angle and the trans-influence of the central atom in the pincer platform also affect the coordination mode of the BH4- ligand. The nickel complexes tend to adopt a monodentate coordination mode while the palladium and platinum complexes can adopt either the monodentate or the bidentate mode depending on the structural features of the pincer platforms. Longer M-P bonds and smaller P-M-P bite angles favour the bidentate mode. The stability of the BH4- ligand is influenced by both the coordination mode and the nature of the metal centre. The BH3 species is released more easily from complexes with less electron rich metal centres. Following the series of Ni, Pd, and Pt, complexes with the same pincer ligand more easily lose a BH3 moiety.

Performance Evaluation of Cross-Linked Polyethylene Insulation of Operating 110 kV Power Cables.

The ageing characteristic of XLPE insulation of operating a 110 kV power cable with different service time is studied in this paper. The microscopic morphology of XLPE films from different cables were characterized by using Differential Scanning Calorimetry (DSC), X-ray Diffraction method (XRD), and Fourier Transform Infrared Spectroscopy (FTIR) methods, and the dielectric, mechanical, and electrical properties of XLPE were also measured. The relationship of several typical property parameters with the cable service time were established, and the ageing mechanism of XLPE insulation of the operating cable was also analyzed. It was found that XLPE insulation would endure a recrystallization process in the initial operation stage during which the microscopic morphology would become more perfect with higher crystallinity and denser crystal structure. Then, the thermal oxidation would dominate the ageing process of XLPE with the molecular chains broken and more micromolecular products generated after the cable had operated for more than 10-15 years. The AC breakdown strength decreases with the increase of cable service time, with lower decreasing rate in the initial operation stage and a larger rate after 10-15 years. The Pearson correlation coefficient between the cable service time with the characteristic parameters were calculated, and some of them were found to be effective to be used as indicators for operation state detection of operating power cables.

The Nocebo Response in Pharmacologic Treatments of Primary Headache: A Systematic Review and Meta-Analysis.

The nature and magnitude of nocebo responses in primary headache disorders are still unknown. To assess the distribution and possible predictors of nocebo responses in primary headache treatments, databases, including PubMed, EMBASE, and Cochrane Library were searched from 1988 to December 31, 2020, for parallel-group, double-blind, randomized placebo-controlled trials of pharmacologic treatments of primary headaches. The nocebo responses were calculated using a random effects meta-analysis model. Subgroup and metaregression analyses were performed to determine the associations of study design and demographic characteristics with nocebo responses. A total of 178 randomized controlled trials that satisfied the inclusion criteria were included. Prophylactic treatments elicited stronger nocebo responses than acute treatments. The majority of nocebo adverse events were mild to moderate in severity, with the nervous and digestive systems being the most commonly affected. There was a strong correlation between the active medication and control groups in terms of adverse events, both quantitatively and qualitatively. Long treatment duration, a high proportion of subjects receiving active medications, multicenter design, North America, high body mass index, women, previous treatment experiences, and a high proportion of patients with migraine headache with aura were all found to be significant positive predictors of nocebo responses, whereas the year of publication was found to be inversely related to them. Nocebo effects should be noticed for their contribution to discontinuation of or lack of adherence to active treatments. Clarifying these nocebo-related risk factors can aid in their clinical prevention and management.

Understanding the magnetic anisotropy for linear sandwich [Er(COT)]+-based compounds: a theoretical investigation.

A series of linear sandwich single-ion magnets containing [Er(COT)]+ fragment were selected to probe the magneto-structural correlations using ab initio methods. For prolate shaped ErIII ion, an equatorially coordinating geometry is preferable to achieve high axial anisotropy. Our calculations confirm that the increasing transversal crystal field (CF) induced by equatorial ligands truly enhances the energy barrier. However, if we continue to strengthen the transversal CF in the equatorial plane, the energy barrier inversely decreases. Our further results show that a medium ligand ring of benzene is preferable for prolate shaped ErIII ion, which can induce the modest energy splitting and the small temperature-assisted quantum tunneling of magnetization. Although the obtained energy barrier of 343.1 cm-1 for our created model [(C6H6)Er(COT)]+ is the largest, it is also much smaller than the DyIII-based compounds.

Pyromellitic Diimide-Extended Pillar[6]arene: Synthesis, Structure, and Its Complexation with Polycyclic Aromatic Hydrocarbons.

A novel pyromellitic diimide-extended pillar[6]arene was synthesized in two steps with moderate yield for the first time. It showed a symmetrical stretched hexagon structure and could form 1:2 complexes with polycyclic aromatic hydrocarbons in solution. Interestingly, a linear supramolecular array between complex 1@G42 and pyrene through π···π stacking interactions was also observed in the solid state.

Doubly bi-allelic variants of MTHFR and MTHFD1 in a Chinese patient with hyperhomocysteinemia and failure of folic acid therapy.

Background: Hyperhomocysteinemia (HHcy) is a risk factor for thromboembolic disease. Defects in one-carbon metabolism (1-CM)-related genes, such as methylenetetrahydrofolate reductase (MTHFR), methylenetetrahydrofolate dehydrogenase, cyclohydrolase, and formyltetrahydrofolate synthetase 1 (MTHFD1), can cause HHcy and may also affect the efficacy of folic acid therapy. The details of mechanisms are yet to be further investigated. Method: We described a Chinese family with hereditary HHcy. The proband suffered from severe thromboembolic disease and experienced failure of folic acid therapy. Two sons of the proband were also diagnosed with HHcy but were sensitive to folic acid therapy. Whole-exome sequencing (WES) was conducted to evaluate the genetic lesion of this family. Results: Compound heterozygous variants (a common polymorphism, p. A222V, and a novel variant, p. C631*fs*1) of the MTHFR gene and a homozygous missense variant (p. K134R) of the MTHFD1 gene were identified in the proband. The two sons, with successful intervention, only harbored the homozygous p. A222V variant of the MTHFR gene. Conclusion: The clinical manifestations and genetic research synergistically confirmed the diagnosis of HHcy and clarified the failure of folic acid therapy in the proband caused by doubly bi-allelic variants of the MTHFR and MTHFD1 genes. Our study increased our understanding of the molecular basis of 1-CM-related gene defects on folic acid therapy in HHcy.

The Stability of Diphosphino-Boryl PBP Pincer Backbone: PBP to POP Ligand Hydrolysis.

Since moisture may frequently be present in many solvents, it is important to know the reactivity of a catalyst against water for catalytic reactions. In order to explore the stability and understand the transformation process of diphosphino-boryl-based PBP pincer platform, [PdCl{B(NCH2 Pt Bu2 )2 -o-C6 H4 }] (1) was treated with PdCl2 , HB(NCH2 PPh2 )2 -o-C6 H4 was reacted with [PdCl2 (cod)] (cod=cyclo-octa-1,5-diene) and [Pd2 (dba)3 ] (dba=dibenzylideneacetone), respectively, in the presence of water. Some novel palladium POP complexes, [Pd2 Cl2 (µ-Cl){µ-κ3 -P,O,P-OB(NCH2 Pt Bu2 )2 -o-C6 H4 }] (2 a), [Pd4 (µ-Cl)2 (µ-O)2 {µ-κ3 -P,O,P-OB(NCH2 PPh2 )2 -o-C6 H4 }2 ] (2 b), [Pd2 {µ-κ4 -P,P,P,P-O(B(NCH2 PPh2 )2 -o-C6 H4 )2 }{µ-κ2 -P,P-(NHCH2 PPh2 )2 -o-C6 H4 }] (3), were obtained. It was found that the PBP pincer backbone can easily be converted into a POP backbone in the presence of water. From the crystal structures of the resultant palladium complexes, possible pincer backbone transformation pathways were discussed.

Damage Effect of ALD-Al2O3 Based Metal-Oxide-Semiconductor Structures under Gamma-Ray Irradiation.

The radiation response of Al2O3 on silicon substrate under gamma-rays is studied in this article. The atomic layer deposited Al2O3 based metal-oxide-semiconductor structures were irradiated under gamma-ray with the total dose of 1.2 Mrad(Si)/2.5 Mrad(Si)/4 Mrad(Si). The generation, transportation and trapping characteristics of radiation induced charges were studied by using electronic, physical and chemical methods. Firstly, the radiation induced trapped charge density in Al2O3 is up to 1012 cm-2, with the effective trapping efficiency of 7-20% under irradiation. Secondly, the leakage current through Al2O3 changes little with the increase of radiation total dose. Thirdly, oxygen vacancy in Al2O3 and O dangling bonds and Al-Si metallic bonds at Al2O3/Si interface are dominant radiation induced defects in Al2O3/Si system, and the valence band offset between Al2O3 and Si is found to decrease after irradiation. From the results we can see that Al2O3 is radiation resistant from the aspect of leakage current and crystallization characteristics, but the radiation induced charge trapping and new defects in Al2O3/Si structure cannot be ignored. This paper provides a reference for the space application of Al2O3 based MOS devices.

Evolution from a single relaxation process to two-step relaxation processes of Dy2 single-molecule magnets via the modulations of the terminal solvent ligands.

To explore the influences of magnetic interactions on the relaxation dynamics of single-molecule magnets (SMMs) and to understand the relationship between single-ion relaxation and the relaxation of a molecular entity, it is very important to design dinuclear lanthanide-based SMMs with two-step relaxation processes. Here, three Dy2 complexes of compositions [Dy2(L)2(NO3)2(MeOH)2] (1), [Dy2(L)2(NO3)2(EtOH)2] (2), and [Dy2(L)2(NO3)2(DMF)2]·0.5EtOH (3) (H2L = 2-(((2-hydroxy-3-methoxybenzyl)imino)methyl)-4-methoxyphenol) were successfully synthesized via elaborately introducing different terminal solvent ligands. X-ray single-crystal diffraction analyses revealed that complexes 1-3 are isostructural. The two DyIII ions of 1 and 2 both adopt D2d symmetry, while the two DyIII centres of 3 display D2d and D4d symmetries, respectively. The magnetic property studies of 1-3 indicated that all three complexes exhibit single-molecule magnet (SMM) behaviours with energy barriers of 104 K for 1, 98.94 K for 2, and 76.28 K and 45.54 K for 3 under zero dc field. The target of assembling Dy2 SMMs with two-step relaxation processes was achieved by gradually increasing the sizes of the terminal solvent ligands. Complex 3 exhibits two-step relaxation processes. Complete active space self-consistent field (CASSCF) calculations were performed on 1-3 to rationalize the observed differences in the magnetic behaviour. It is found that both the angles θ between the magnetic axis and the vector connecting two DyIII ions and the symmetries of DyIII ions are vital factors that affect the energy barriers of 1-3. The high local symmetries of the central metals in 1 and 2 make the complexes act as SMMs with higher energy barriers, while the smaller θ angle and different symmetries of the two DyIII ions render complex 3 as a SMM with a two-step relaxation process. This work demonstrates a new methodology for preparing SMMs with two-step relaxation processes by fine-tuning the terminal solvent ligands.