Dual Catalysis Based on N‑Heterocyclic Olefins for the Copolymerization of Lactones: High Performance and Tunable Selectivity

The cooperative interaction of four structurally different N-heterocyclic olefins (NHOs) with a range of simple metal halides as Lewis acidic cocatalysts is employed for the homo- and copolymerization of ε-caprolactone (CL) and δ-valerolactone (VL). While the single components are inactive on their own, their combination provides a powerful and operationally simple platform for the controlled preparation of polyesters from these monomers, whereby molecular weights and end groups can be predicted in a room temperature-based process using low catalyst loadings (0.25–0.50 mol %). A narrow molecular weight distribution is observed (1.05 < <i>Đ</i>_M < 1.15) for multiple combinations of NHOs and Lewis acids. Importantly, the supposed mechanism involves activation of the lactone monomers via coordination to the metal-based Lewis acids. This ensures rapid polymerization and additionally decouples reactivity and activity; a trade-off between fast monomer consumption and the suppression of side reactions (transesterification) can be circumvented this way. Furthermore, this dual catalytic setup can be used to direct preferential monomer incorporation when CL/VL are copolymerized. From the same 1:1 mixture of both monomers, either VL or CL can be consumed more rapidly, or more random incorporation can be achieved, depending on the employed cocatalysts. Well-defined copolymers with moderate gradients result, where the copolymerization selectivity is dictated by choice of the Lewis acid present, which is remarkable in view of the very different NHOs involved (saturated five- and six-membered rings, benzimidazole and imidazole derivatives). While most metal halides (such as MgI₂, ZnI₂, and AlCl₃) entail VL-enriched polyester, YCl₃ favors CL incorporation

<i>N</i>‑Heterocyclic Olefin-Based (Co)polymerization of a Challenging Monomer: Homopolymerization of ω‑Pentadecalactone and Its Copolymers with γ‑Butyrolactone, δ‑Valerolactone, and ε-Caprolactone

A setup consisting of <i>N</i>-heterocylic olefins (NHOs) and several simple Lewis acids (such as MgCl₂ or LiCl) was employed to homopolymerize ω-pentadecalactone (PDL) and to copolymerize it with five-, six-, and seven-membered lactones (γ-butyrolactone (GBL), δ-valerolactone (VL), and ε-caprolactone (CL)). Also, the copolymerization of GBL with VL and CL was investigated separately. This dual catalytic approach succeeded for the entropically driven high-temperature polymerization of PDL in course of fast, operationally simple polymerization procedures. PPDL could be generated in short reaction times to reach high conversion (85–97%), whereby the polymerization rates are significantly modulated by the metal halide cocatalyst (ranging from virtually 0 to >80% conversion after 15 min, 1% NHO loading). Application of mildly activating Lewis acids ensured that the frequently encountered excessive transesterification was reduced to yield relatively well-controlled polyester (<i>M</i>_n up to 40 kg/mol, <i>Đ</i>_M = 1.5–1.8). The 1:1 copolymerization of PDL and GBLunifying two lactones with thermodynamically opposite polymerization preferenceswas observed to be strongly dependent on the applied Lewis pair, with yield (15–50%) and GBL content (5–22%, by ¹³C NMR) determined by the Lewis acid. Likewise, GBL/CL and GBL/VL copolymers displayed varying, catalyst-dependent compositions and were obtained as well-defined polyester (<i>Đ</i>_M = 1.1–1.2) with intermediate molecular weight (2–8 kg/mol) if a suitable cocatalyst pair was chosen. One-pot 1:1 PDL/VL copolymerizations resulted in high or low PDL content, as well as virtually exclusive VL consumption, if Lewis pairs containing YCl₃, ZnI₂, or MgI₂ were employed, with the reaction temperature a convenient tool to further manipulate the polymer structure. Finally, PDL/CL copolymers were readily formed, reaching high or quantitative conversion (<i>M</i>_n = 10–30 kg/mol) whereby 50% PDL content and perfectly random polymer structures were accessible. For selected copolymers the thermal properties were elucidated by DSC measurements

Specimens of <i>Sinobirma malaisei</i>; (A, C, D, F) = dorsal view, (B, E, G) = ventral view.

<p>Scale bars = 1 cm; specimens approximately to the same scale. (A–B): holotype ♀, Myanmar, Kachin State (S), Kambaiti; in NHRS. (C): ♀, China, Yunnan, Tongbinguan nature reserve; in MNHN. (D–E): ♂, China, Yunnan, Gaoligongshan; in CSNB. (F–G): ♂, China, Yunnan, Yingjiang, Xima; in CSNB. (H): ova, China, Yunnan. (I–K): 1^st larval instar, rearing attempt from the eggs in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0043920#pone-0043920-g001" target="_blank">Fig. 1H</a>.</p

BIMBINGAN DAN KONSELING ISLAM DENGAN RATIONAL EMOTIVE BEHAVIOR THERAPY DALAM MENANGANI SIKAP FEMINISME PADA SEORANG PEMUDA DI DESA BALONGMASIN KECAMATAN PUNGGINNG MOJOKERTO

Fokus penelitian adalah (1) Bagaimana proses Bimbingan konseling Islam Dengan Rational Emotive Behavior Therapy Dalam Menangani Sikap Feminisme Pada Seorang Pemuda Di Desa Balongmasin Kecamatan Pungging Mojokerto?, (2) Bagaimana hasil akhir proses Bimbingan konseling Islam Dengan Rational Emotive Behavior Therapy Dalam Menangani Sikap Feminisme Pada Seorang Pemuda Di Desa Balongmasin Kecamatan Pungging Mojokerto ? Peneliti menggunakan metode penelitian kualitatif dengan jenis penelitian studi kasus dan dianalisa menggunakan deskriptif komparatif. Adapun pengumpulan data melalui wawancara, observasi, dan dokumentasi. Dalam penelitian ini disimpulkan bahwa proses Bimbinga Dan Konseling Islam Dengan Rational Emotive Behavior Therapy Dalam Menangani sikap Feminisme Pada Seorang Pemuda dilakukan dengan menggunakan langkah-langkah konseling yaitu, identifikasi masalah, diagnosis, prognosis, terapi/treatment dan evaluasi/follow up. Dalam pemberian terapi/treatment peneliti menggunakan konseling keluarga dengan menggunaka Rational Emotive Behavior Therapy. Adapun hasil akhir dari proses konseling dalam penelitian ini dinilai cukup berhasil. Hasil tersebut dapat dilihat dari adanya perubahan yang terjadi pada klien yaitu bersikap feminisme yang dilakukan klien sedikit-demi sedikit menjadi berkurang dan menghilang

Female genitalia of <i>Sinobirma malaisei</i>, China, Yunnan, Tongbinguan nature reserve; (A) ventral view, (B) lateral view (drawings reproduced from

<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0043920#pone.0043920-Rougerie1" target="_blank">[<b>5</b>]</a><b>).</b> Scale bars = 1 mm.</p

Percentage of divergence in DNA barcode sequences.

<p>Kimura 2-parameter (K2P) distances (%) for barcode DNA sequences of the three analyzed species in genus <i>Sinobirma</i>; minimal pairwise distances between species are given for each species pair; values in square brackets represent maximal intraspecific distances.</p

♂ genitalia of <i>Sinobirma</i> species; each panel represent a posterior view of the main genital structure at the top, the phallus immediately below, and the posterior end of 8^th sternite and tergite at the bottom.

<p>Scale bars = 1 mm. (A): <i>S. malaisei</i>. China, Yunnan, Gaoligongshan; no. 2024/09 Naumann. (B): <i>S. myanmarensis</i>. Myanmar, Kachin, Chudu Razi Range, no. 2022/09 Naumann. (C): <i>S. bouyeri</i>. India, Arunachal Pradesh, near Rapum, no. 2021/09 Naumann. (D): <i>S. myanmarensis</i>. Myanmar, Sagaing, E Ngalung Ga, no. 2023/09 Naumann.</p

Specimens of <i>Sinobirma bouyeri</i>; (A, C, E, G, H) = dorsal view, (B, D, F, I, J) = ventral view.

<p>Scale bars = 1 cm; specimens approximately to the same scale. (A–B): holotype (HT) ♀, China, Tibet, Tomi; photo T. Bouyer; in SMFL. (C–F): paratype (PT) ♀♀, same data as HT; in CSNB & CTBO. (G–J): PT ♂♂, India, Arunachal Pradesh, near Rapum; in CSNB & CSLL.</p

Phylogenetic analyses of sequence data.

<p>All trees shown are ML trees obtained from the analysis of (a) COI barcode sequences, (b) 28S rDNA sequences, and (c) the combination of both genes; values above branches are bootstrap supports for each node. Branch lengths represent the number of substitutions per site. Trees (b) and (c) are unrooted.</p

Summary of the material examined and of diagnostic morphological characters between the three <i>Sinobirma</i> species studied.

<p>Summary of the material examined and of diagnostic morphological characters between the three <i>Sinobirma</i> species studied.</p