Penerapan Model Pembelajaran Atraktif Berbasis Multiple Intelligences Tentang Pemantulan Cahaya pada Cermin

Penelitian ini bertujuan untuk mengetahui efektivitas penerapan model pembelajaran atraktif berbasis multiple intelligences dalam meremediasi miskonsepsi siswa tentang pemantulan cahaya pada cermin. Pada penelitian ini digunakan bentuk pre-eksperimental design dengan rancangan one group pretest-post test design. Alat pengumpulan data berupa tes pilihan ganda dengan reasoning. Hasil validitas sebesar 4,08 dan reliabilitas 0,537. Siswa dibagi menjadi lima kelompok kecerdasan, yaitu kelompok linguistic intelligence, mathematical-logical intelligence, visual-spatial intelligence, bodily-khinestetic intelligence, dan musical intelligence. Siswa membahas konsep fisika sesuai kelompok kecerdasannya dalam bentuk pembuatan pantun-puisi, teka-teki silang, menggambar kreatif, drama, dan mengarang lirik lagu. Efektivitas penerapan model pembelajaran multiple intelligences menggunakan persamaan effect size. Ditemukan bahwa skor effect size masing-masing kelompok berkategori tinggi sebesar 5,76; 3,76; 4,60; 1,70; dan 1,34. Penerapan model pembelajaran atraktif berbasis multiple intelligences efektif dalam meremediasi miskonsepsi siswa. Penelitian ini diharapkan dapat digunakan pada materi fisika dan sekolah lainnya

Fe₅Mo Cluster with Iron-Carbide and Molybdenum-Carbide Bonding Motifs: Structure and Selective Alkyne Reductions

Herein we report the synthesis, X-ray structure, and characterization of the title pentairon (molybdo)­carbido cluster. The reaction of the pentairon (μ₅-carbido) dianion [Fe₅(μ₆-C)­(μ₂-CO)₂(CO)₁₂]^2– (<b>1</b>) with [Mo­(CO)₃(chpt)] (chpt = cycloheptatriene) forms the heterohexanuclear cluster [K­(benzo-18-crown-6)]₂[Fe₅Mo­(μ₆-C)­(μ₂-CO)₃(CO)₁₄] (<b>2</b>). The dianion exhibits a Fe₅Mo­(μ₆-C) core structure supported by three bridging (ν_CO = 1788 cm^–1) and terminal (ν_CO = 1943 cm^–1) CO ligands. Cluster <b>2</b> provides the selective reduction of diphenylacetylene to <i>cis</i>-diphenylethylene via a spectroscopically observed cluster-hydride intermediate (¹H NMR: δ −26)

Ab Initio Chemical Synthesis of Designer Metal Phosphate Frameworks at Ambient Conditions

Stepwise hierarchical and rational synthesis of porous zinc phosphate frameworks by predictable and directed assembly of easily isolable tetrameric zinc phosphate [Zn­(dipp)­(solv)]₄ (dippH₂ = diisopropylphenyldihydrogen phosphate; solv = CH₃OH or dimethyl sulfoxide) with D4R (double-4-ring) topology has been achieved. The preformed and highly robust D4R secondary building unit can be coordinatively interconnected through a varied choice of bipyridine-based ditopic spacers L1–L7 to isolate eight functional zinc phosphate frameworks, [Zn₄(dipp)₄(L1)_1.5(DMSO)]·4H₂O (<b>2</b>), [Zn₄(dipp)₄(L2)_1.5(CH₃OH)] (<b>3</b>), [Zn₄(dipp)₄(L1)₂] (<b>4</b>), [Zn₄(dipp)₄(L3)₂] (<b>5</b>), [Zn₄(dipp)₄(L4)₂] (<b>6</b>), [Zn₄(dipp)₄(L5)₂] (<b>7</b>), [Zn₄(dipp)₄(L6)₂] (<b>8</b>), and [Zn₄(dipp)₄(L7)₂] (<b>9</b>), in good yield. The preparative procedures are simple and do not require high pressure or temperature. Surface area measurements of these framework solids show that the guest accessibility of the frameworks can be tuned by suitable modification of bipyridine spacers

An OCO^3– Trianionic Pincer Tungsten(VI) Alkylidyne: Rational Design of a Highly Active Alkyne Polymerization Catalyst

Synthesis, characterization, and catalytic alkyne polymerization results for the first trianionic pincer alkylidyne complex, [^<i>t</i>BuOCO]­WCC­(CH₃)₃(THF)₂ (<b>6</b>), are described. Complex <b>6</b> is a highly active catalyst for the polymerization of acetylenes and exhibits a high turnover number (4371), activity (1.05 × 10⁶ g_PPA mol_cat^–1 h^–1), and yield (87%) for the polymerization of 1-ethynyl-4-fluorobenzene

Exploring Trends in Metal–Metal Bonding, Spectroscopic Properties, and Conformational Flexibility in a Series of Heterobimetallic Ti/M and V/M Complexes (M = Fe, Co, Ni, and Cu)

To understand the metal–metal bonding and conformational flexibility of first-row transition metal heterobimetallic complexes, a series of heterobimetallic Ti/M and V/M complexes (M = Fe, Co, Ni, and Cu) have been investigated. The titanium tris­(phosphinoamide) precursors ClTi­(XylNP^<i>i</i>Pr₂)₃ (<b>1</b>) and Ti­(XylNP^<i>i</i>Pr₂)₃ (<b>2</b>) have been used to synthesize Ti/Fe (<b>3</b>), Ti/Ni (<b>4</b>, <b>4</b>^<b>THF</b>), and Ti/Cu (<b>5</b>) heterobimetallic complexes. A series of V/M (M = Fe (<b>7</b>), Co (<b>8</b>), Ni (<b>9</b>), and Cu (<b>10</b>)) complexes have been generated starting from the vanadium tris­(phosphinoamide) precursor V­(XylNP^<i>i</i>Pr₂)₃ (<b>6</b>). The new heterobimetallic complexes were characterized and studied by NMR spectroscopy, X-ray crystallography, electron paramagnetic resonance, and Mössbauer spectroscopy, where applicable, and computational methods (DFT). Compounds <b>3</b>, <b>4</b>^<b>THF</b>, <b>7</b>, and <b>8</b> are <i>C</i>₃-symmetric with three bridging phosphinoamide ligands, while compounds <b>9</b> and <b>10</b> adopt an asymmetric geometry with two bridging phosphinoamides and one phosphinoamide ligand bound η² to vanadium. Compounds <b>4</b> and <b>5</b>, on the other hand, are asymmetric in the solid state but show evidence for fluxional behavior in solution. A correlation is established between conformational flexibility and metal–metal bond order, which has important implications for the future reactivity of these and other heterobimetallic molecules

Synthesis and Structural Characterization of High Spin M/Cu (M = Mn, Fe) Heterobimetallic and Fe/Cu₂ Trimetallic Phosphinoamides

The heterobimetallic complexes [Mn­(^<i>i</i>PrNPPh₂)₃Cu­(^<i>i</i>PrNHPPh₂)] (<b>1</b>) and [Fe­(^<i>i</i>PrNPPh₂)₃Cu­(^<i>i</i>PrNHPPh₂)] (<b>2</b>) have been synthesized by the one pot reaction of LiN^<i>i</i>PrPPh₂, MCl₂ (M = Mn, Fe), and CuI in high yield. Addition of excess CuI into <b>2</b> or directly to the reaction mixture led to the formation of a heterotrimetallic [Fe­(^<i>i</i>PrNPPh₂)₃Cu₂(^<i>i</i>PrNPPh₂)] (<b>3</b>) in good yield. Complexes <b>1</b>–<b>3</b> have been characterized by means of elemental analysis, paramagnetic ¹H NMR, UV–vis spectroscopy, cyclic voltammetry, and single crystal X-ray analysis. In all three complexes, Mn or Fe are in the +2 oxidation state and have a high spin electron configuration, as evidenced by solution Evans’ method. In addition, the oxidation state of Fe in complex <b>3</b> is confirmed by zero-field ⁵⁷Fe Mössbauer spectroscopy. X-ray crystallography reveals that the three coordinate Mn/Fe centers in the zwitterionic complexes <b>1</b>–<b>3</b> adopt an unusual trigonal planar geometry

Utilization of Phosphinoamide Ligands in Homobimetallic Fe and Mn Complexes: The Effect of Disparate Coordination Environments on Metal–Metal Interactions and Magnetic and Redox Properties

A series of homobimetallic phosphinoamide-bridged diiron and dimanganese complexes in which the two metals maintain different coordination environments have been synthesized. Systematic variation of the steric and electronic properties of the phosphinoamide phosphorus and nitrogen substituents leads to structurally different complexes. Reaction of [^<i>i</i>PrNKPPh₂] (<b>1</b>) with MCl₂ (M = Mn, Fe) affords the phosphinoamide-bridged bimetallic complexes [Mn­(^<i>i</i>PrNPPh₂)₃Mn­(^<i>i</i>PrNPPh₂)] (<b>3</b>) and [Fe­(^<i>i</i>PrNPPh₂)₃Fe­(^<i>i</i>PrNPPh₂)] (<b>4</b>). Complexes <b>3</b> and <b>4</b> are iso-structural, with one metal center preferentially binding to the three amide ligands in a trigonal planar arrangement while the second metal center is ligated by three phosphine donors. A fourth phosphinoamide ligand caps the tetrahedral coordination sphere of the phosphine-ligated metal center. Mössbauer spectroscopy of complex <b>4</b> suggests that the metals in these complexes are best described as Fe^II centers. In contrast, treatment of MnCl₂ or FeI₂ with [MesNKP^<i>i</i>Pr₂] (<b>2</b>) leads to the formation of the halide-bridged species [(THF)­Mn­(μ-Cl)­(MesNP^<i>i</i>Pr₂)₂Mn­(MesNP^<i>i</i>Pr₂)] (<b>5</b>) and [(THF)­Fe­(μ-I)­(MesNP^<i>i</i>Pr₂)₂FeI (<b>7</b>), respectively. Utilization of FeCl₂ in place of FeI₂, however, leads exclusively to the C₃-symmetric complex [Fe­(MesNP^<i>i</i>Pr₂)₃FeCl] (<b>6</b>), structurally similar to <b>4</b> but with a halide bound to the phosphine-ligated Fe center. The Mössbauer spectrum of <b>6</b> is also consistent with high spin Fe^II centers. Thus, in the case of the [^<i>i</i>PrNPPh₂]⁻ and [MesNP^<i>i</i>Pr₂]⁻ ligands, zwitterionic complexes with the two metals in disparate coordination environments are preferentially formed. In the case of the more electron-rich ligand [^<i>i</i>PrNP^<i>i</i>Pr₂]⁻, complexes with a 2:1 mixed donor ligand arrangement, in which one of the ligand arms has reversed orientation relative to the previous examples, are formed exclusively when [^<i>i</i>PrNLiP^<i>i</i>Pr₂] (generated in situ) is treated with MCl₂ (M = Mn, Fe): (THF)₃LiCl­[Mn­(N^<i>i</i>PrP^<i>i</i>Pr₂)₂(P^<i>i</i>Pr₂N^<i>i</i>Pr)­MnCl] (<b>8</b>) and [Fe­(N^<i>i</i>PrP^<i>i</i>Pr₂)₂(P^<i>i</i>Pr₂N^<i>i</i>Pr)­FeCl] (<b>9</b>). Bimetallic complexes <b>3</b>–<b>9</b> have been structurally characterized using X-ray crystallography, revealing Fe–Fe interatomic distances indicative of metal–metal bonding in complexes <b>6</b> and <b>9</b> (and perhaps <b>4</b>, to a lesser extent). All of the complexes appear to adopt high spin electron configurations, and magnetic measurements indicate significant antiferromagnetic interactions in Mn₂ complexes <b>5</b> and <b>8</b> and no discernible magnetic superexchange in Fe₂ complex <b>4</b>. The redox behavior of complexes <b>3</b>–<b>9</b> has also been investigated using cyclic voltammetry, and theoretical investigations (DFT) were performed to gain insight into the metal–metal interactions in these unique asymmetric complexes

Metal–Metal Bonding in Low-Coordinate Dicobalt Complexes Supported by Phosphinoamide Ligands

Homobimetallic dicobalt complexes featuring metal centers in different coordination environments have been synthesized, and their multielectron redox chemistry has been investigated. Treatment of CoX₂ with MesNKP^<i>i</i>Pr₂ leads to self-assembly of [(THF)­Co­(MesNP^<i>i</i>Pr₂)₂­(μ-X)­CoX] [X = Cl (<b>1</b>), I (<b>2</b>)], with one Co center bound to two amide donors and the other bound to two phosphine donors. Upon two-electron reduction, a ligand rearrangement occurs to generate the symmetric species (PMe₃)­Co­(MesNP^<i>i</i>Pr₂)₂­Co­(PMe₃) (<b>3</b>), where each Co has an identical mixed P/N donor set. One-electron oxidation of <b>3</b> to generate a mixed valence species promotes a ligand reararrangement back to an asymmetric configuration in [(THF)­Co­(MesNP^<i>i</i>Pr₂)₂­Co­(PMe₃)]­[PF₆] (<b>4</b>). Complexes <b>1</b>–<b>4</b> have been structurally characterized, and their metal–metal interactions are discussed in the context of computational results

Synthesis and Structural Characterization of High Spin M/Cu (M = Mn, Fe) Heterobimetallic and Fe/Cu₂ Trimetallic Phosphinoamides

The heterobimetallic complexes [Mn­(^<i>i</i>PrNPPh₂)₃Cu­(^<i>i</i>PrNHPPh₂)] (<b>1</b>) and [Fe­(^<i>i</i>PrNPPh₂)₃Cu­(^<i>i</i>PrNHPPh₂)] (<b>2</b>) have been synthesized by the one pot reaction of LiN^<i>i</i>PrPPh₂, MCl₂ (M = Mn, Fe), and CuI in high yield. Addition of excess CuI into <b>2</b> or directly to the reaction mixture led to the formation of a heterotrimetallic [Fe­(^<i>i</i>PrNPPh₂)₃Cu₂(^<i>i</i>PrNPPh₂)] (<b>3</b>) in good yield. Complexes <b>1</b>–<b>3</b> have been characterized by means of elemental analysis, paramagnetic ¹H NMR, UV–vis spectroscopy, cyclic voltammetry, and single crystal X-ray analysis. In all three complexes, Mn or Fe are in the +2 oxidation state and have a high spin electron configuration, as evidenced by solution Evans’ method. In addition, the oxidation state of Fe in complex <b>3</b> is confirmed by zero-field ⁵⁷Fe Mössbauer spectroscopy. X-ray crystallography reveals that the three coordinate Mn/Fe centers in the zwitterionic complexes <b>1</b>–<b>3</b> adopt an unusual trigonal planar geometry

Utilization of Phosphinoamide Ligands in Homobimetallic Fe and Mn Complexes: The Effect of Disparate Coordination Environments on Metal–Metal Interactions and Magnetic and Redox Properties

A series of homobimetallic phosphinoamide-bridged diiron and dimanganese complexes in which the two metals maintain different coordination environments have been synthesized. Systematic variation of the steric and electronic properties of the phosphinoamide phosphorus and nitrogen substituents leads to structurally different complexes. Reaction of [^<i>i</i>PrNKPPh₂] (<b>1</b>) with MCl₂ (M = Mn, Fe) affords the phosphinoamide-bridged bimetallic complexes [Mn­(^<i>i</i>PrNPPh₂)₃Mn­(^<i>i</i>PrNPPh₂)] (<b>3</b>) and [Fe­(^<i>i</i>PrNPPh₂)₃Fe­(^<i>i</i>PrNPPh₂)] (<b>4</b>). Complexes <b>3</b> and <b>4</b> are iso-structural, with one metal center preferentially binding to the three amide ligands in a trigonal planar arrangement while the second metal center is ligated by three phosphine donors. A fourth phosphinoamide ligand caps the tetrahedral coordination sphere of the phosphine-ligated metal center. Mössbauer spectroscopy of complex <b>4</b> suggests that the metals in these complexes are best described as Fe^II centers. In contrast, treatment of MnCl₂ or FeI₂ with [MesNKP^<i>i</i>Pr₂] (<b>2</b>) leads to the formation of the halide-bridged species [(THF)­Mn­(μ-Cl)­(MesNP^<i>i</i>Pr₂)₂Mn­(MesNP^<i>i</i>Pr₂)] (<b>5</b>) and [(THF)­Fe­(μ-I)­(MesNP^<i>i</i>Pr₂)₂FeI (<b>7</b>), respectively. Utilization of FeCl₂ in place of FeI₂, however, leads exclusively to the C₃-symmetric complex [Fe­(MesNP^<i>i</i>Pr₂)₃FeCl] (<b>6</b>), structurally similar to <b>4</b> but with a halide bound to the phosphine-ligated Fe center. The Mössbauer spectrum of <b>6</b> is also consistent with high spin Fe^II centers. Thus, in the case of the [^<i>i</i>PrNPPh₂]⁻ and [MesNP^<i>i</i>Pr₂]⁻ ligands, zwitterionic complexes with the two metals in disparate coordination environments are preferentially formed. In the case of the more electron-rich ligand [^<i>i</i>PrNP^<i>i</i>Pr₂]⁻, complexes with a 2:1 mixed donor ligand arrangement, in which one of the ligand arms has reversed orientation relative to the previous examples, are formed exclusively when [^<i>i</i>PrNLiP^<i>i</i>Pr₂] (generated in situ) is treated with MCl₂ (M = Mn, Fe): (THF)₃LiCl­[Mn­(N^<i>i</i>PrP^<i>i</i>Pr₂)₂(P^<i>i</i>Pr₂N^<i>i</i>Pr)­MnCl] (<b>8</b>) and [Fe­(N^<i>i</i>PrP^<i>i</i>Pr₂)₂(P^<i>i</i>Pr₂N^<i>i</i>Pr)­FeCl] (<b>9</b>). Bimetallic complexes <b>3</b>–<b>9</b> have been structurally characterized using X-ray crystallography, revealing Fe–Fe interatomic distances indicative of metal–metal bonding in complexes <b>6</b> and <b>9</b> (and perhaps <b>4</b>, to a lesser extent). All of the complexes appear to adopt high spin electron configurations, and magnetic measurements indicate significant antiferromagnetic interactions in Mn₂ complexes <b>5</b> and <b>8</b> and no discernible magnetic superexchange in Fe₂ complex <b>4</b>. The redox behavior of complexes <b>3</b>–<b>9</b> has also been investigated using cyclic voltammetry, and theoretical investigations (DFT) were performed to gain insight into the metal–metal interactions in these unique asymmetric complexes