Effect of an Internet-based mental health promotion intervention among immigrant Chinese women: A quasi-experimental study.

Background: Owing to a lack of social support, child-rearing Chinese women in Japan experience mental health disorders, such as depression and parenting stress. Effective interventions to improve the mental health of these women are lacking. This study aimed to develop an Internet-based mental health promotion intervention for this subsection of the population and evaluate the effectiveness of the intervention. Methods: We used a quasi-experimental pre- and post-test design whereby the results of the intervention group were compared with those of a control group. Seventy-three child-rearing women were recruited from online groups of Chinese residents in Japan. In the Internet-based intervention, participants utilised an information provision application and attended online parenting workshops. The intervention group participated in the online workshops once a week for six weeks and accessed the application, whereas the control group did not. The outcome measures included the levels of mental health distress, depression, social support, and parenting stress. Data were collected from February to April 2022. Data analysis was performed using repeated-measures analysis of variance. Results: Mental health distress (F = 16.478, p < 0.001, η2 = 0.210) and depression (F = 13.078, p = 0.001, η2 = 0.174) were significantly affected in the intervention group compared with the control group. There were no significant differences in social support and parenting stress between the groups. The Internet-based mental health promotion intervention was highly appraised by the participants. Conclusions: This study developed an Internet-based mental health promotion intervention that involved an information provision application and parenting workshops. The intervention significantly reduced the mental health distress and depression of Chinese women in Japan but did not affect social support and parenting stress. The findings suggest that this intervention could be applied to foreign women with multicultural backgrounds in diverse settings to improve their psychological well-being.

Rare-Earth Metal Complexes Supported by A Tridentate Amidinate Ligand: Synthesis, Characterization, and Catalytic Comparison in Isoprene Polymerization.

To systematically investigate the dependence of the initiating group and metal size on polymerization performance, a family of rare-earth metal bis(alkyl)/bis(benzyl)/bis(amide) complexes supported by a monoanionic tridentate amidinate ligand [(2,6-iPr2C6H3)NC(Ph)N(C6H4-2-OMe]- (HL) were synthesized and well-characterized. Treatment of rare-earth metal tris(alkyl)/tris(benzyl)/tris(amide) complexes Y(CH2C6H4NMe2-o)3 or Y(CH2SiMe3)3(THF)2 or Ln[N(SiHMe2)2]3(THF)x (Ln = Sc, x = 1; Ln = Y, La, Sm, Lu, x = 2) with 1 equiv of HL gave the corresponding mono(amidinate) rare-earth metal bis(alkyl)/bis(benzyl)/bis(amide) complexes [(2,6-iPr2C6H4)NC(Ph)N(C6H4-2-OMe)]Y(CH2C6H4NMe2-o)2 (1), [(2,6-iPr2C6H4)NC(Ph)N(C6H4-2-OMe)]Y(CH2SiMe3)2(THF) (2), and [(2,6-iPr2C6H4)NC(Ph)N(C6H4-2-OMe)]Ln[N(SiHMe2)2]2(THF)n (Ln = Y, n = 1 (3); Ln = La, n = 1 (4); Ln = Sc, n = 0 (5); Ln = Lu, n = 0 (6); Ln = Sm, n = 0 (7)) in good isolated yields. These complexes were characterized by elemental analysis, NMR spectroscopy, and single-crystal X-ray diffraction. In the presence of excess AlMe3 and on treatment with 1 equiv of [Ph3C][B(C6F5)4], these complexes could serve as precatalysts for cationic polymerization of isoprene, in which the dependence of the polymerization activity and regioselectivity on the initiating group and metal size was observed.

Syndiospecific Copolymerization of Styrene with para-Methoxystyrene Catalyzed by Functionalized Fluorenyl-Ligated Rare-Earth Metal Complexes.

The development of efficient catalysts for the copolymerization of nonpolar monomers with polar monomers remains a great challenging task in polymer synthesis. A one-pot reaction of anhydrous LnCl3 with pyridyl-methylene-functionalized octamethylfluorenyl lithium OctFlu-CH2PyLi in a 1:1 molar ratio, followed by alkylation with 2 equiv of LiCH2SiMe3 in THF afforded the fluorenyl-ligated rare-earth metal bis(alkyl) complexes (OctFlu-CH2Py)Ln(CH2SiMe3)2(THF) [Ln = Sc (1), Y (2)]. Both complexes were isolated as neutral species and were characterized by NMR spectrum and elemental analysis. Complex 2 was subjected to single-crystal X-ray diffraction, which showed that the whole modified fluorenyl ligand was coordinated to Y3+ in the η5/κ1 mode to form a constrained geometry configuration. In the presence of excess AliBu3, and on activation with 1 equiv of [Ph3C][B(C6F5)4] in toluene, complexes 1 and 2 became active for both styrene (St) and para-methoxystyrene (pMOS) polymerization, giving polymers with high syndiotacticity (rrrr > 99%) without solvent extraction. Moreover, the ternary catalyst system composed of complex 2/AliBu3/[Ph3C][B(C6F5)4] was highly effective for the syndiospecific copolymerization of styrene with pMOS, producing random copolymers with high molecular weights and narrow molecular weight distributions. The contents of pMOS in the copolymers could be easily tuned in a wide range (11-93 mol %) by simply changing the pMOS-to-St feed ratios.

Interventions to improve immigrant women's mental health: A systematic review.

AIMS: To identify the effectiveness of interventions for improving immigrant women's mental health and explore the role of these interventions in nursing practice. BACKGROUND: Immigrant women rearing children and living in a foreign country experience many mental health problems during pregnancy, child-rearing, and acculturation. Mental health problems can be controlled or modified through effective practices. Few studies have examined the role of different types of interventions in alleviating these mental health issues in immigrant women in the perinatal period, and it is unclear whether such interventions are effective. METHODS: This systematic review used the Preferred Reporting Items for Systematic Reviews and Meta-Analysis checklist. Studies form December 1948-August 2021 were retrieved from four databases: MEDLINE, CINAHL, EMBASE, and Cochrane Library. This systematic review's protocol was registered at PROSPERO (CRD42020210845). The data were summarised using narrative analysis. RESULTS: Eight studies met the inclusion criteria and were included in the final analyses. There were few mental health improvement interventions for immigrant women. The interventions included home visit programmes, asset-building mental health interventions, cognitive-behavioural interventions, nursing interventions, perinatal education interventions, and mindfulness interventions. Home visit programmes and asset-building mental health interventions have reported positive outcomes in improving depressive symptoms and mental health. CONCLUSIONS: There are few interventions for improving immigrant women's mental health. Most existing interventions are conducted through group education, but there are no explicit significant effects. Home visits may be an effective approach for conducting interventions to improve immigrant women's mental health. An effective nursing intervention should be developed, and more research is needed in improving immigrant women's mental health. RELEVANCE TO CLINICAL PRACTICE: This review provides evidence for nurses and midwives to practice appropriate and effective approaches and strategies for improving immigrant women's mental health. We suggest possible future interventions for this cohort of immigrant women in the perinatal period.

Promotion of Parenting and Mental Health Needs among Chinese Women Living in Japan: A Qualitative Study.

Chinese women raising children in Japan tend to experience high parenting stress and poor mental well-being. However, their specific parenting and mental health promotion needs remain unknown. This study aimed to explore the parenting and mental health promotion needs of Chinese women living in Japan and provide recommendations to guide interventions. Semi-structured in-depth interviews were conducted. Participants included 15 women aged 28-39 years who were pregnant or rearing a child younger than six years old. Thematic analysis was performed for data analysis. More than half of the participants experienced mental health problems, such as depressive symptoms and child-rearing stress. Four themes relating to their needs were identified: concrete support, information provision, caring and understanding, and social network building. Information provision and social network building should be emphasized as practical social support mechanisms to improve these women's mental health. Furthermore, a mental health promotion intervention should be developed to address this vulnerable population's needs. Healthcare providers and public health workers should help improve the social support systems of Chinese women in Japan to prevent mental health problems. Potential transcultural education can, arguably, help healthcare providers better understand transcultural care.

Syntheses of Heterometallic Neodymium-Zinc Complexes and Their Performance in the Copolymerization of CO2 and Cyclohexene Oxide.

A series of Nd-Zn heterometallic complexes bearing o-phenylenediamine-bridged tris(phenolato) ligands (L) were synthesized and characterized. By tuning the backbones of ancillary tris(phenolato) ligands and initiating benzyloxy groups, a Nd-Zn heterometallic complex 12 (ClLNdZnOBnCF3) was found to be highly active for the copolymerization of CO2 and cyclohexene oxide (CHO) to produce perfect alternating poly(cyclohexene carbonate) with a high turnover frequency up to 5640 h-1 under the polymerization of 90 °C and 20 bar CO2 pressure. The kinetics study showed that CO2/CHO copolymerization catalyzed by 12 was the first order dependence of 12 and CHO concentration and the zero-order dependence of CO2 pressure. The reaction of 12 with CO2 generated a carbonate-coordinated [NdZnNd] trinuclear complex 13, which was believed to be the key intermediate to initiate CO2/CHO copolymerization. On the basis of some experiments, a plausible synergistic polymerization mechanism was proposed.

Nickel-Catalyzed Reductive Csp2-Csp3 Cross Coupling Using Phosphonium Salts.

A nickel-catalyzed reductive cross coupling with phosphonium salts and allylic C(sp3)-O bond electrophiles, which granted direct construction of the C(sp2)-C(sp3) bond, is successfully developed. The protocol features broad substrate scope, high-functional-group tolerance, and heterocycle compatibility. Notably, the much more challenging reductive cross coupling with heterocyclic thiazolylphosphonium salts has also been accomplished for the first time.

Reduction of Amides to Amines with Pinacolborane Catalyzed by Heterogeneous Lanthanum Catalyst La(CH2C6H4NMe2-o)3@SBA-15.

Hydroboration of amides is a useful synthetic strategy to access the corresponding amines. In this contribution, it was found that the supported lanthanum benzyl material La(CH2C6H4NMe2-o)3@SBA-15 was highly active for the hydroboration of primary, secondary, and tertiary amides to amines with pinacolborane. These reactions selectively produced target amines and showed good tolerance for functional groups such as -NO2, -halogen, and -CN, as well as heteroatoms such as S and O. This reduction procedure exhibited the recyclable and reusable property of heterogeneous catalysts and was applicable to gram-scale synthesis. The reaction mechanisms were proposed based on some control experiments and the previous literature. This is the first example of hydroborative reduction of amides to amines mediated by heterogeneous catalysts.

Health-Related Quality of Life and Risk Factors among Chinese Women in Japan Following the COVID-19 Outbreak.

The COVID-19 pandemic has significantly affected individuals' physical and mental health, including that of immigrant women. This study aimed to evaluate the health-related quality of life (HRQoL), identify the demographic factors and awareness of the COVID-19 pandemic contributing to physical and mental health, and examine the risk factors associated with poor physical and mental health of Chinese women in Japan following the COVID-19 pandemic outbreak. Using an electronic questionnaire survey, we collected data including items on HRQoL, awareness of the COVID-19 pandemic, and demographic factors. One hundred and ninety-three participants were analyzed. Approximately 98.9% of them thought that COVID-19 affected their daily lives, and 97.4% had COVID-19 concerns. Married status (OR = 2.88, 95%CI [1.07, 7.72], p = 0.036), high concerns (OR = 3.99, 95%CI [1.46, 10.94], p = 0.007), and no concerns (OR = 8.75, 95%CI [1.17, 65.52], p = 0.035) about the COVID-19 pandemic were significantly associated with poor physical health. Unmarried status (OR = 2.83, 95%CI [1.20, 6.70], p = 0.018) and high COVID-19 concerns (OR = 2.17, 95%CI [1.04, 4.56], p = 0.040) were significantly associated with poor mental health. It is necessary to provide effective social support for Chinese women in Japan to improve their well-being, especially in terms of mental health.

Relationships of Social Support, Stress, and Health among Immigrant Chinese Women in Japan: A Cross-Sectional Study Using Structural Equation Modeling.

Social support could help immigrant Chinese women in Japan to improve health. However, these women suffer from numerous stresses associated with acculturation and child-rearing, which could impact the effect of social support on mental and physical health. This study aims to identify the relationships among social support, acculturative stress, parenting stress, mental health, and physical health to propose a structural path model of these relationships and to evaluate the mediating role of stress between social support and health. A questionnaire was used to collect data for the main variables and demographic factors. A total of 109 women participated (mean age 33.9 ± 5.6 years). The results show that immigrant Chinese women in Japan experienced a low level of mental health (44.7 ± 9.8). Additionally, social support directly influenced parenting stress (ß = -0.21, p < 0.05), acculturative stress (ß = -0.19, p < 0.05), and mental health (ß = 0.31, p < 0.001) and indirectly influenced physical health (ß = 0.09, p < 0.05). Parenting stress partially mediated the association between social support and mental health (ß = 0.09, p < 0.05). To protect the effectiveness of social support on mental health, it is essential to reduce the parenting stress of immigrant Chinese women.

Redox-controlled syndio-specific polymerization of styrene catalyzed by ferrocenyl functionalized half-sandwich scandium complexes.

Redox-controlled polymerization is one of the new and efficient strategies to precisely construct the microstructures of polymeric materials, and thus has received increasing attention in the chemical community. Salt metathesis of ScCl3 with 1 equiv. of Fc(1-C9H6)Li (where Fc = ferrocenyl group), followed by the addition of 2 equiv. of LiCH2C6H4NMe2-o in THF at room temperature gave the ferrocenyl functionalized half-sandwich scandium bis(o-dimethylaminobenzyl) complex [Fc(1-C9H6)]Sc(CH2C6H4NMe2-o)2 (1) in 89% isolated yield. This complex was characterized by elemental analysis, FT-IR spectroscopy, NMR spectroscopy and single-crystal X-ray diffraction. Treatment of 1 with 1 equiv. of [Ph3C][B(C6F5)4] in THF generated the THF-coordinated cationic half-sandwich scandium mono(o-dimethylaminobenzyl) complex {[Fc(1-C9H6)]Sc(CH2C6H4NMe2-o)}{[B(C6F5)4]} (2-THF2). Switching in situ between the oxidized and reduced forms of active THF-free species (originally generated from 1/[Ph3C][B(C6F5)4] in situ) resulted in the redox-controlled syndio-specific polymerization of styrene.

Lanthanum complexes stabilized by a pentadentate Schiff-base ligand: synthesis, characterization, and reactivity in statistical copolymerization of ε-caprolactone and l-lactide.

Developing catalysts that are capable of catalyzing the copolymerization of ε-caprolactone and l-lactide to give random CL/LA copolymers is of great importance. One-pot reaction of La[N(SiMe3)2]3 with 1 equiv. of LH2 (LH2 = NH(CH2CH2N[double bond, length as m-dash]CHC6H2-3,5-tBu2-2-OH)2) in THF at room temperature, followed by protolysis with one equivalent amount of ROH (R = C6H2-2,6-tBu2-4-CH3, tBu, iPr, Bn, and Et) at 60 °C gave the mono-Schiff-base-ligated lanthanum aryloxide complex LLa(OC6H2-2,6-tBu2-4-CH3)(THF) (1), and lanthanum alkyloxide complexes LLaOtBu(THF) (2), [LLaOiPr]2 (3), [LLaOBn]2 (4), and [LLaOEt]2 (5) in 59-69% isolated yields. These lanthanum complexes were capable of initiating the homopolymerization of l-lactide and rac-lactide with extremely high activity, and the copolymerization of ε-caprolactone (ε-CL) and l-lactide (l-LA) to give statistical CL/LA copolymers via a transesterification reaction.

Bimetallic Arylamide-Ligated Rare-Earth Metal Complexes: Synthesis, Characterization, and Stereo-Selectively Switchable Property in 2-Vinylpyridine Polymerization.

Bimetallic complexes are expected to offer unique catalytic property, by facilitating cooperative effects between proximate functional groups or adjacent active metal centers, and thus have attracted increasing attention in the chemical community. Treatment of Ln(CH2SiMe3)3(THF)2 or Ln(CH2C6H4NMe2-o)3 with 1,4-(C6H5NH)2C6H4 in a 2:1 molar ratio in tetrahydrofuran (THF) generated a series of bimetallic arylamide-ligated rare-earth metal alkyl complexes [1,4-(C6H5N)2C6H4][Ln(CH2SiMe3)2(THF)2]2 (Ln = Sc (1), Lu (2), Y (3)), and aminobenzyl complexes [1,4-(C6H5N)2C6H4][Ln(CH2C6H4NMe2-o)2(THF)x]2 (Ln = Sc (4), x = 0; Lu (5), Y (6), x = 1) in 65-73% isolated yields. To reveal the polymerization difference between bimetallic and monometallic rare-earth metal complexes, the monoarylamide-ligated scandium bis(aminobenzyl) complex [(C6H5)2N]Sc(CH2C6H4NMe2-o)2 (7) was prepared by the reaction of Sc(CH2C6H4NMe2-o)3 with 1 equiv of diphenylamine (C6H5)2NH. All these rare-earth metal complexes were characterized by elemental analysis and NMR spectroscopy. The molecular structures of complexes 4 and 6 were authenticated by single-crystal X-ray diffraction. Complexes 2, 3, 5, and 6 alone were highly active for 2-vinylpyridine (2VP) polymerization at room temperature, giving poly-2VP with good iso-selectivity (mm). After activation with 2 equiv of [Ph3C][B(C6F5)4] or [PhNHMe2][B(C6F5)4], these complexes demonstrated an improved iso-selectivity (mm up to 96%) toward 2VP polymerization compared to their neutral analogues. In comparison, the bimetallic scandium complexes 1 and 4 showed relatively poor activity toward 2VP polymerization under the same conditions. However, the stereoselectivity of the polymerization could be switched from iso-tacticity to syndio-rich selectivity solely by tuning active species from only one scandium precatalyst. The catalyst system of complex 4/[PhNMe2H][B(C6F5)4] was able to promote a controlled syndio-specific polymerization of 2VP. The polymerization was experimentally verified to proceed via group transfer mechanism. Preliminary results indicated that the bimetallic rare-earth metal complexes showed a higher polymerization activity than the corresponding monometallic species mostly resulting from the cooperative effect.

Highly selective redistribution of primary arylsilanes to secondary arylsilanes catalyzed by Ln(CH2C6H4NMe2-o)3@SBA-15.

Rare-earth metal tris(aminobenzyl) complexes Ln(CH2C6H4NMe2-o)3 (Ln = La, Y) were grafted onto the dehydroxylated periodic mesoporous silica support SBA-15 to generate the organometallic-inorganic hybrid materials Ln(CH2C6H4NMe2-o)3@SBA-15 (Ln = La (2a), Y (2b)), which demonstrated extremely high selectivity (>99%) in catalyzing the redistribution of primary arylsilanes to secondary arylsilanes without the requisition of strict control of the reaction conditions. The hybrid materials still showed a perfect selectivity and activity after three catalytic cycles.

Controlled iso-specific polymerization of 2-vinylpyridine catalyzed by arylamide-ligated rare-earth metal aminobenzyl complexes.

Treatment of rare-earth tris(o-dimethylaminobenzyl) complexes Ln(CH2C6H4NMe2-o)3 with one equivalent of the pyrrolyl-functionalized arylamide ligands 2,5-Me2C4H2NCH2CH2NHC6H5 and 2,5-Me2C4H2NSiMe2NHC6H5 in toluene generated arylamide rare-earth metal bis(aminobenzyl) complexes (2,5-Me2C4H2NCH2CH2NC6H5)Ln(CH2C6H4NMe2-o)2 (Ln = Sc (1), La (2), Lu (3)) and (2,5-Me2C4H2NSiMe2NC6H5)Ln(CH2C6H4NMe2-o)2 (Ln = Lu (5), Y (6)) in good isolated yields. Reaction of Y(CH2C6H4NMe2-o)3 with 2,5-Me2C4H2NCH2CH2NHC6H5 in 1 : 1 or 1 : 2 molar ratio specifically yielded bis(arylamide) yttrium mono(aminobenzyl) complex (2,5-Me2C4H2NCH2CH2NC6H5)2Y(CH2C6H4NMe2-o) (4). Complexes 1-6 were characterized by elemental analysis and NMR spectroscopy. Complexes 2, 4 and 5 were structurally validated by single crystal X-ray diffraction. These complexes were highly active for polymerization with 2-vinylpyridine to afford iso-tactic polymers with high molecular weight and narrow molecular weight distribution. Complex 4 promoted the polymerization in a controlled fashion, and the iso-selectivity of the polymerization reached up to a Pm value of 0.98. Analyses of the oligomer by NMR and MALDI-TOF showed that the polymerization proceeded via a group transfer polymerization mechanism.

Perfectly isoselective polymerization of 2-vinylpyridine promoted by ß-diketiminato rare-earth metal cationic complexes.

Symmetric and asymmetric ß-diketiminato rare-earth metal dialkyl complexes L1Ln(CH2SiMe3)2(THF) (L1 = (2,6-Et2C6H3)NC(Me)CHC(Me)N(2,6-Et2C6H3), Ln = Y (1a), Lu (1b)) and L2Ln(CH2SiMe3)2(THF) (L2 = (2,6-iPr2C6H3)NC(Me)CHC(Me)N(C6H5), Ln = Y (2a), Lu (2b)) have been synthesized by the reaction of the precursor Ln(CH2SiMe3)3(THF)2 with the corresponding pro-ligands (HL1 and HL2) in good yield. These complexes promote the polymerization of 2-vinylpyridine (2-VP) to produce isotactic-biased poly(2-vinylpyridine) (P2VP) (mm: 40%) in quantitative yield. The in situ generated cationic species with the addition of borate ([Ph3C][B(C6F5)4], [PhNHMe2][B(C6F5)4]) prior to the polymerization display distinct results, and the symmetric ones afford perfectly isotactic P2VP with an mm value up to 99%, whilst the asymmetric ones produce atactic P2VP (mm: 26%). The 1H NMR spectrum and MALDI-TOF mass analysis of an oligomer prepared with 1a/[Ph3C][B(C6F5)4] indicate that the polymerization is initiated by coordination insertion of 2-VP into the Y-CH2SiMe3 bond of the in situ generated cationic species.

Stereo-selectivity switchable ROP of rac-ß-butyrolactone initiated by salan-ligated rare-earth metal amide complexes: the key role of the substituents on ligand frameworks.

A series of novel salan-ligated rare-earth metal amide complexes were prepared and employed as initiators for the ROP of rac-ß-butyrolactone (rac-BBL). Tuning the substituents on the N atoms of the ligand frameworks from aromatic groups to aliphatic groups results in switching tacticity from iso-tactic to syndio-tactic in rac-BBL polymerization.

Addition of C-H Bonds of Pyridine Derivatives to Alkenes Catalyzed by Zirconium Complexes Bearing Amine-Bridged Bis(phenolato) Ligands.

Cationic zirconium complexes in situ generated from zirconium dibenzyl complexes bearing amine-bridged bis(phenolato) ligands have been developed to catalyze addition of C(sp2)-H and C(sp3)-H bonds of pyridine derivatives to alkenes. A series of zirconium complexes bearing different ligands have been synthesized, and their activities in catalyzing addition of C(sp3)-H bonds of pyridine derivatives to alkenes have been studied and compared. Both reaction activity and regioselectivity are influenced by electronic and steric properties of ligand backbones. In addition, a cationic zirconium complex has been isolated and structurally characterized to shed some light on reaction mechanism.

Rare-earth metal bis(aminobenzyl) complexes supported by pyrrolyl-functionalized arylamide ligands: synthesis, characterization and styrene polymerization performance.

An acid-base reaction between the rare-earth tris(o-dimethylaminobenzyl) complexes Ln(CH2C6H4NMe2-o)3 and the pyrrolyl-functionalized arylamide ligands 2,5-Me2C4H2NCH2SiMe2NHC6H4R (R = H, (HL1); R = Cl-p, (HL2)) was investigated. Treatment of HL1 and HL2 with 1 equiv. of Ln(CH2C6H4NMe2-o)3 in toluene at room temperature gave (2,5-Me2C4H2CH2NSiMe2NC6H5)Ln(CH2C6H4NMe2-o)2 (Ln = Sc (1), La (2), Lu (3)) and (2,5-Me2C4H2NCH2SiMe2NC6H4Cl-p)Ln(CH2C6H4NMe2-o)2 (Ln = Sc (4), La (5), Lu (6)) in good isolated yields. These complexes were characterized by elemental analysis and NMR spectroscopy. 2, 4 and 5 were structurally authenticated by single crystal X-ray diffraction. NMR and X-ray diffraction show that there are no interactions between the central metal and the pyrrolyl moiety in small sized metal complexes, while in large lanthanum complexes, besides the coordination of the arylamide moiety to La3+ in η1-bonding mode through a N atom, the pyrrolyl ring also has close contact with La3+ in 2 and 5. The binary systems of 1-6/[Ph3C][B(C6F5)4] were employed as catalysts for syndio-specific polymerization of styrene, and the pyrrolyl-ligated lanthanum complexes showed much higher activity than the complexes in which the pyrrolyl moiety had no coordination with the central metal.

Rare-earth metal bis(silylamide) complexes supported by mono-dentate arylamido ligand: synthesis, reactivity, and catalyst precursors in living cis-1,4-selective polymerization of isoprene.

The salt metathesis reaction of LnCl3 with 1 equivalent of arylamido lithium [2,6-(i)Pr2C6H3N(SiMe3)]Li followed by addition of 2 equivalents of LiN(SiHMe2)2 in THF at room temperature obtained neutral mono-arylamido-ligated rare-earth metal bis(silylamide) complexes [2,6-(i)Pr2C6H3N(SiMe3)]Ln[N(SiHMe2)2]2(THF) (Ln = Y (), Lu (), La ()) in good isolated yields. Treatment of with excess AlMe3 produced the mono(arylamido) Ln/Al heterotrinuclear methyl complexes [2,6-(i)Pr2C6H3N(SiMe3)]Ln[(µ-Me)2AlMe2]2 (Ln = Y (), Lu (), La ()) via amide-alkyl exchange. All these complexes were well-characterized by elemental analysis, NMR spectroscopy and FT-IR spectroscopy. , and were further structurally authenticated by X-ray crystallography. In the presence of [Ph3C][B(C6F5)4] and Al(i)Bu3, were highly active for cis-1,4-selective polymerization of isoprene, whereas /[Ph3C][B(C6F5)4]/Al(i)Bu3 promoted the polymerization in a living fashion.