Motivasi merupakan dorongan dari diri seseorang yang dapat meningkatkan keinginan dan kemauan untuk melakukan sesuatu. Motivasi berpengaruh dalam tercapainya tujuan pembelajaran. Peningkatan motivasi ...belajar dapat terjadi dengan adanya media pembelajaran. Tujuan dari penelitian ini untuk mengembangkan media flipchart berbasis komik untuk meningkatkan motivasi belajar peserta didik pada materi sila-sila Pancasila. Model dalam penelitian ini adalah 3-D (Define, Design, Develop. Validasi dilakukan oleh ahli materi dan ahli media. Kemudian dilakukan uji coba kepada peserta didik kelas II SDM PK Baturan. Hasil validasi ahli media mendapatkan nilai rata-rata 91,33% dan ahli materi memperoleh nilai rata-rata 93,75%. Hasil respon peserta didik mendapatkan kategori sangat layak dengan skor rata-rata 90,9% dan respon guru mendapatkan skor 91%. Hasil angket motivasi belajar mendapatkan skor 73% yang sebelumnya mendatkan skor 66%. Hasil penelitian tersebut disimpulkan bahwa media flipchart berbasis komik pada materi sila-sila Pancasila dapat meningkatkan motivasi belajar peserta didik kelas II di SDM PK Baturan. Keywords: Media, Flipchart komik, Motivasi, Sila-sila Pancasila
Abstract
Nickel-catalyzed decarbonylative alkynylation of acyl fluorides with terminal silylethynes under copper-free conditions is described. This newly developed method has a wide substrate scope, ...affording internal silylethynes in moderate to high yields. The formation of 1,3-diynes as homocoupled products and conjugate enones as carbonyl-retentive products were effectively suppressed.
Application of silyl functionalities is one of the most promising strategies among various 'elements chemistry' approaches for the development of novel and distinctive drug candidates. Replacement of ...one or more carbon atoms of various biologically active compounds with silicon (so-called sila-substitution) has been intensively studied for decades, and is often effective for alteration of activity profile and improvement of metabolic profile. In addition to simple C/Si exchange, several novel approaches for utilizing silicon in medicinal chemistry have been suggested in recent years, focusing on the intrinsic differences between silicon and carbon. Sila-substitution offers great potential for enlarging the chemical space of medicinal chemistry, and provides many options for structural development of drug candidates.
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•A comprehensive timeline of the transition metal-catalyzed ring-opening of four-membered silacycles is presented.•A comprehensive timeline of the transition metal-catalyzed ...ring-expansion reactions of four-membered silacycles is presented.•The synthesis of different types of silacyclobutane and its analogues under various reaction conditions is discussed.•The synthetic application of silacyclobutane and its analogues as organosilicon reagent in transition-metal catalysis is highlighted.•The mechanistic rationale of silicon-carbon bond cleavage and activations by transition-metal-based catalysts is outlined.
Silacyclobutanes (SCB), a family of useful organosilicon compounds, have attracted much attention because the highly strained silicon-carbon bond can be activated, as evidenced by transition-metal catalyzed ring-opening and ring expansion reactions. Efforts of extending silicon-carbon bond activation will definitely trigger powerful and privileged catalyst systems capable of unveiling opportunities for highly efficient and valuable transformations of SCB. This review summarized and highlighted representative and important advances for the synthesis of silacyclobutanes and its analogues as well as their catalytic transformations enabled by various transition-metal complexes whose versatility will be demonstrated widely in organosilicon chemistry and transition-metal catalysis. The different contributions in this growing research area summarized in this review could provide inspiration and incentive to make SCB as a precious source of organosilicon compounds.
The continuous innovation of captivating new organic semiconducting materials remains pivotal in the development of high‐performance organic electronic devices. Herein, a molecular engineering by ...combining sila‐annulation with the vertical extension of rylene diimides (RDIs) toward high‐mobility organic semiconductors is presented. The unilateral and bilateral sila‐annulated quaterrylene diimides (Si‐QDI and 2Si‐QDI) are designed and synthesized. In particular, the symmetrical bilateral 2Si‐QDI exhibits a compact, 1D slipped π–π stacking arrangement through the synergistic combination of a sizable π‐conjugated core and intercalating alkyl chains. Combining the appreciable elevated HOMO levels and reduced energy gaps, the single‐crystalline organic field‐effect transistors (SC‐OFETs) based on 2Si‐QDI demonstrate exceptional ambipolar transport characteristics with an impressive hole mobility of 3.0 cm2 V−1 s−1 and an electron mobility of 0.03 cm2 V−1 s−1, representing the best ampibolar SC‐OFETs based on RDIs. Detailed theoretical calculations rationalize that the larger transfer integral along the π–π stacking direction is responsible for the achievement of the superior charge transport. This study showcases the remarkable potential of sila‐annulation in optimizing carrier transport performances of polycyclic aromatic hydrocarbons (PAHs).
A molecular engineering toward high‐mobility organic semiconductors by combining sila‐annulation with the vertical extension of rylene diimides is presented. The resultant 2Si‐QDI exhibits tunable energy levels and packing arrangement. The single‐crystalline organic field‐effect transistors demonstrate exceptional ambipolar transport characteristics with an impressive hole mobility of 3.0 cm2 V−1 s−1 and an electron mobility of 0.03 cm2 V−1 s−1.
Laporan postingan riset penelitian ini bertujuan untuk mengenal serta menganalisis pemikiran ataupun gagasan Haji Abdul Malik Karim Amrullah maupun yang lebih banyak dikenal Buya Hamka, khususnya ...yang berkaitan dengan nilai-nilai pembelajaran yang tercantum dalam ajaran Islam baik secara eksplisit maupun implisit dengan mengimplementasikan sila-sila Pancasila. Riset ini memakai tata cara kualitatif lalu memakai pendekatan deskriptif. Tata cara ini dicoba dengan metode menganalisis informasi ataupun bahan diperoleh dari berbagai referensi seperti buku, jurnal, dan/atau artikel. Berdasarkan hasil analisis dapat disimpulkan bahwa pemikiran Buya Hamka tentang pendidikan yang diperoleh dari nilai-nilai ajaran Islam sangat relevan dengan kondisi terkini dan dapat diterapkan dalam dunia pendidikan mutkahir dalam hal ini pun adanya sila-sila Pancasila. Pemikiran-pemikiran Buya Hamka tersebut jika diterapkan dengan tepat dapat mewujudkan manusia yang bermoral atau berakhlak mulia, berkarakter, cerdas, serta berwawasan luas. Lambang bangsa Indonesia yaitu Garuda Pancasila dimana terdapat sila-sila Pancasila. Kebaruan dan dampak dari hasil penelitian ini kita dapat membandingkan dan mengetahui apa saja implementasi dalam pandangan buya hamka dalam sila-sila Pancasila
α‐Sila‐Dipeptides: Synthesis and Characterization Minkovich, Boris; Ruderfer, Ilya; Kaushansky, Alexander ...
Angewandte Chemie International Edition,
October 1, 2018, 2018-10-01, 2018-10-00, 20181001, Volume:
57, Issue:
40
Journal Article
Peer reviewed
The first two α‐sila‐dipeptides, 7 and cyclo‐sila‐dipeptide 8, were synthesized and characterized by several methods, including X‐ray crystallography. Bulky t‐BuMe2Si substituents provide some ...kinetic stabilization to the synthesized molecules. 7 and 8 are the first examples of a “Si for C switch” in the central α‐position of an amino acid or a peptide, in which silicon is bonded to both the amino and the carbonyl groups.
Two α‐sila‐dipeptides: The acyclic 1 and the cyclic 2 were synthesized, isolated and characterized by X‐ray crystallography. 1 and 2 are the first examples of a “Si for C switch” at the central α‐position of amino acids and peptides, enriching the library of acyclic‐ and cyclic‐dipeptides (diketopiperazines), including biologically active compounds.
Laccases and laccase-mediator systems (LMS) are versatile catalysts that can oxidize a broad range of substrates coupled to the sole reduction of dioxygen to water. They possess many biotechnological ...applications in paper, textile, and food industries, bioethanol production, organic synthesis, detection and degradation of pollutants, and biofuel cell development. In particular, bacterial laccases are getting relevance due to their activity in a wide range of pH and temperature and their robustness under harsh conditions. However, the enzyme and the redox mediator's availability and costs limit their large-scale commercial use. Here we demonstrate that β-(10-phenothiazyl)-propionic acid can be used as an efficient and low-cost redox mediator for decolorizing synthetic dyes by the recombinant laccase SilA from Streptomyces ipomoeae produced in E. coli. This new LMS can decolorize more than 80% indigo carmine and malachite green in 1 h at pH = 8.0 and 2 h in tap water (pH = 6.8). Furthermore, it decolorized more than 40% of anthraquinone dye remazol brilliant blue R and 80% of azo dye xylidine ponceau in 5 h at 50 °C, pH 8.0. It supported at least 3 decolorization cycles without losing activity, representing an attractive candidate for a cost-effective and environmentally friendly LMS functional at neutral to alkaline pH.
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•Bacterial laccase-β-(10-phenothiazyl)-propionic acid LMS show high efficiency.•β-(10-phenothiazyl)-propionic acid withstand several reuses at alkaline pH.•Bacterial LMS achieved high decolorization of synthetic dyes in tap water and pH 8.•Phenothiazine derivatives are less expensive than other common redox mediators.
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