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

Organic-Soluble Tri-, Tetra-, and Pentanuclear Titanium(IV) Phosphates

Bulky 2,6-disubstituted aryl esters of phosphoric acid, 2,6-dimethylphenyl phosphate (dmppH2), and 2,6-diisopropylphenyl phosphate (dippH2) react differently with Cp*TiCl3 (Cp* = C5Me5) under identical reaction conditions. While dippH2 and Cp*TiCl3 react in THF at 25 °C to yield air-stable trinuclear titanophosphate cage [(Ti3Cp*Cl(μ2-O)(dipp)2(dippH)4(THF)]·(toluene) (1), the similar reaction involving dmppH2 yields the tetranuclear titanophosphate [Ti4Cl2(μ2-O)2(dmpp)2(dmppH)6(THF)2]·(toluene)2 (2). Interestingly, the change of titanium source to Ti(OiPr)4 in the reaction with dippH2 produces a pentanuclear titanophosphate, [Ti5(μ3-O)(OiPr)6((dipp)6(THF)] (3). Compounds 1−3 were the only products isolated as single crystals from the respective reaction mixtures in 59, 75, and 54% yield, respectively. The new clusters 1−3 have been characterized by elemental analysis, IR and NMR (1H and 31P) spectroscopy, and single crystal X-ray diffraction studies. The structural elucidation reveals that in the reactions leading to 1 and 2, extensive Cp*-Ti bond cleavage occurs, leaving only one residual Cp*-ligand in cluster 1 and none in 2. Closer analysis of the structures of 1−3 shows common structural features which in turn imply that the formation of all three products could have proceeded via a common Ti−O−Ti dimeric building block

Cooperative Binding of Phosphate Anion and a Neutral Nitrogen Donor to Alkaline-Earth Metal Ions. Investigation of Group 2 Metal−Organophosphate Interaction in the Absence and Presence of 1,10-Phenanthroline

Alkaline-earth metal phosphates containing nitrogen-donor ligands have been prepared by the reaction of alkaline-earth metal acetates M(OAc)2·xH2O (M = Mg, Ca, Sr, Ba) with 2,6-diisopropylphenyl phosphate (dippH2) in the absence and presence of 1,10-phenanthroline (phen). Interaction of strontium or barium acetate with dippH2 in methanol at room temperature leads to the isolation of ionic phosphates [{M2(μ-H2O)4(H2O)10}{dipp}2]·4L [M = Sr, L = CH3OH (1); M = Ba, L = H2O (2)]. The addition of a bidentate nitrogen-donor phen to these reactions leads to the isolation of dinuclear metal phosphates [Mg(dipp)(phen)(CH3OH)2]2 (3) and [M(dippH)2(phen)2(H2O)]2 [M = Ca (4), Sr (5), Ba (6)]. While ionic phosphates 1 and 2 are soluble in water, the predominately covalent dimeric compounds 3−6 are insoluble in all common solvents including water. The new compounds have been characterized in the solid state by elemental analysis, IR, UV−vis, and emission spectroscopy, and single-crystal X-ray diffraction studies. The cationic part in 1 and 2 is a {M2(μ-H2O)4(H2O)10} unit, where each metal ion is surrounded by four bridging and five terminal water molecules as ligands. The dipp anion does not directly bind to the metal ions but is extensively hydrogen-bonded to the cationic unit through the phosphate oxygen and water hydrogen atoms to result in an infinitely layered structure where the hydrophobic aryl group protrudes out of the hydrophilic layer formed by the cationic part and −PO32− units. In contrast, compounds 3−6 are discrete dimeric molecules built around a central M2O4P2 eight-membered ring. While the dippH2 ligand exists in a doubly deprotonated form in 3, two monodeprotonated dippH2 ligands are present per metal ion in compounds 4−6. While 3 prefers only one phen ligand in the metal coordination sphere, two phen ligands chelate each metal ion in 4−6. The conformations of the eight-membered rings in 3−6 vary significantly from each other depending on the size of the cation and the coordination number around the metal. Further, intermolecular hydrogen bonding involving the phenanthroline C−H linkages result, in a gridlike structure in 1, one-dimensional chains in isostructural 2 and 3, and a two-dimensional layer arrangement in 4. Compounds 3−6 are the only examples of alkaline-earth metal phosphate complexes with neutral M−N donor bonds. The thermal behavior of compounds 1−6 has been examined with the help of thermogravimetric analysis and differential scanning calorimetry and also by bulk thermolysis followed by powder X-ray diffraction measurements. While compounds 1 and 2 yield M2P2O7, decomposition of 4−6 results in the formation of M(PO3)2, consistent with the M−P ratio in the precursor complexes

Cooperative Binding of Phosphate Anion and a Neutral Nitrogen Donor to Alkaline-Earth Metal Ions. Investigation of Group 2 Metal−Organophosphate Interaction in the Absence and Presence of 1,10-Phenanthroline

Alkaline-earth metal phosphates containing nitrogen-donor ligands have been prepared by the reaction of alkaline-earth metal acetates M(OAc)2·xH2O (M = Mg, Ca, Sr, Ba) with 2,6-diisopropylphenyl phosphate (dippH2) in the absence and presence of 1,10-phenanthroline (phen). Interaction of strontium or barium acetate with dippH2 in methanol at room temperature leads to the isolation of ionic phosphates [{M2(μ-H2O)4(H2O)10}{dipp}2]·4L [M = Sr, L = CH3OH (1); M = Ba, L = H2O (2)]. The addition of a bidentate nitrogen-donor phen to these reactions leads to the isolation of dinuclear metal phosphates [Mg(dipp)(phen)(CH3OH)2]2 (3) and [M(dippH)2(phen)2(H2O)]2 [M = Ca (4), Sr (5), Ba (6)]. While ionic phosphates 1 and 2 are soluble in water, the predominately covalent dimeric compounds 3−6 are insoluble in all common solvents including water. The new compounds have been characterized in the solid state by elemental analysis, IR, UV−vis, and emission spectroscopy, and single-crystal X-ray diffraction studies. The cationic part in 1 and 2 is a {M2(μ-H2O)4(H2O)10} unit, where each metal ion is surrounded by four bridging and five terminal water molecules as ligands. The dipp anion does not directly bind to the metal ions but is extensively hydrogen-bonded to the cationic unit through the phosphate oxygen and water hydrogen atoms to result in an infinitely layered structure where the hydrophobic aryl group protrudes out of the hydrophilic layer formed by the cationic part and −PO32− units. In contrast, compounds 3−6 are discrete dimeric molecules built around a central M2O4P2 eight-membered ring. While the dippH2 ligand exists in a doubly deprotonated form in 3, two monodeprotonated dippH2 ligands are present per metal ion in compounds 4−6. While 3 prefers only one phen ligand in the metal coordination sphere, two phen ligands chelate each metal ion in 4−6. The conformations of the eight-membered rings in 3−6 vary significantly from each other depending on the size of the cation and the coordination number around the metal. Further, intermolecular hydrogen bonding involving the phenanthroline C−H linkages result, in a gridlike structure in 1, one-dimensional chains in isostructural 2 and 3, and a two-dimensional layer arrangement in 4. Compounds 3−6 are the only examples of alkaline-earth metal phosphate complexes with neutral M−N donor bonds. The thermal behavior of compounds 1−6 has been examined with the help of thermogravimetric analysis and differential scanning calorimetry and also by bulk thermolysis followed by powder X-ray diffraction measurements. While compounds 1 and 2 yield M2P2O7, decomposition of 4−6 results in the formation of M(PO3)2, consistent with the M−P ratio in the precursor complexes

Assembling Discrete D4R Zeolite SBUs through Noncovalent Interactions. 3. Mediation by Butanols and 1,2-Bis(dimethylamino)ethane

The use of tetrameric zinc phosphate [Zn(dipp)(CH3OH)]4 (1; dipp = diisopropylphenylphosphate dianion) as a suitable building block for realizing new noncovalently linked extended structures, via facile replacement of coordinated methanol molecules by other alcohols, is reported herein. Compounds [Zn(dipp)(sec-butanol)]4·4H2O (2) and [Zn(dipp)(tert-butanol)]4·4H2O (3) have been synthesized by the addition of sec- or tert-butanol to 1 at room temperature. The reaction of zinc acetate or zinc sulfate with dippH2 in the presence of N,N,N′,N′-tetramethylethylenediamine (tmeda) under similar reaction conditions results in the formation of [H2tmeda][Zn4(dipp)4(MeOH)2(OAc)2]·(CH3OH) (4) or [H2tmeda][Zn3(dipp)3(dippH)2(CH3OH)]·(CH3OH)3 (5), respectively. Analytically pure compounds 2−5 have been isolated in the form of single crystals directly from the respective reaction mixtures in very good yields and characterized with the aid of analytical and spectroscopic studies. Single-crystal X-ray diffraction studies reveal that compounds 2 and 3 are neutral tetranuclear zinc phosphates. Compound 4 is also a tetrameric phosphate but is anionic. The core structures of compounds 2−4 resemble the double-4-ring secondary building unit (D4R SBU) in zeolites. Compound 5 is a trinuclear ionic zinc phosphate built from three fused S4R SBUs. Compounds 4 and 5 represent the first examples of discrete anionic zinc organophosphates. The presence of coordinated sec- or tert-butanol molecules and a planar water tetramer cluster in 2 and 3, and the H2tmeda cations and methanol solvents in 4 and 5, leads to the formation of zigzag chainlike supramolecular assemblies in the solid state

Activation of an Aryl C−H Bond Converts Chelating Diphenolate Ligands Bound to Zirconium into Trianionic Pincer Ligands: σ-Donor Ligand Effects versus Thermolysis

This report describes the synthesis and characterization of new zirconium benzyl complexes supported by a trianionic pincer ligand. Treating Zr(CH2Ph)4 with the terphenyldiol [tBuOCO]H3 (1) in benzene affords [tBuOCHO]Zr(CH2Ph)2 (2). Thermolysis of 2 leads to formation of dinuclear {[tBuOCO]ZrCH2Ph}2 (3), which contains a five-coordinate zirconium center in a trigonal-bipyramidal (tbp) geometry. Adding 2 equiv of PMe3 to 2 affords [tBuOCO]ZrCH2Ph(PMe3)2 (4-PMe3). X-ray crystallographic analysis reveals strong agostic interactions for the benzyl ligand in both 3 and 4-PMe3. Treatment of 2 with 2 equiv of THF results in hydrocarbon-soluble [tBuOCO]ZrCH2Ph(THF)2 (5). NMR spectroscopic measurements indicate a C2v-symmetric molecule that is isostructural with 4-PMe3. Addition of the larger phosphine PMe2Ph to 2 provides the corresponding mono-PMe2Ph complex in solution, but a small amount of the bis-diphenolate [tBuOCHO]2Zr (6) also forms. Complex 6 was independently synthesized by treating Zr(CH2Ph)4 with 2 equiv of 1. When 2 equiv of pyridine (py) is added to 2, the intermediate [tBuOCHO]ZrCH2Ph(η2−C5H4N)py (7) results from pyridine o-C−H bond activation. After 48 h, complex 7 releases another 1 equiv of toluene by activation of the pincer Cipso−H bond to produce the trianionic pincer complex [tBuOCO]Zr(η2-C5H4N)(py)2 (8). Multinuclear and 2D NMR spectroscopic experiments and combustion analysis support the molecular assignment of 8. Addition of α-picoline to 2 provides different results compared to py. Initially, the α-picoline adduct [tBuOCHO]Zr(CH2Ph)2(α-picoline) (9) forms. Addition of another 1 equiv of α-picoline provides the mixed η2(N,C)-6-Me-pyridyl)/η2(N,C-CH2)-pyrid-2-yl complex [tBuOCHO]Zr(η2(N,C)-6-Me-pyridyl)(η2(N,C-CH2)-pyrid-2-yl) (10)

Activation of an Aryl C−H Bond Converts Chelating Diphenolate Ligands Bound to Zirconium into Trianionic Pincer Ligands: σ-Donor Ligand Effects versus Thermolysis

This report describes the synthesis and characterization of new zirconium benzyl complexes supported by a trianionic pincer ligand. Treating Zr(CH2Ph)4 with the terphenyldiol [tBuOCO]H3 (1) in benzene affords [tBuOCHO]Zr(CH2Ph)2 (2). Thermolysis of 2 leads to formation of dinuclear {[tBuOCO]ZrCH2Ph}2 (3), which contains a five-coordinate zirconium center in a trigonal-bipyramidal (tbp) geometry. Adding 2 equiv of PMe3 to 2 affords [tBuOCO]ZrCH2Ph(PMe3)2 (4-PMe3). X-ray crystallographic analysis reveals strong agostic interactions for the benzyl ligand in both 3 and 4-PMe3. Treatment of 2 with 2 equiv of THF results in hydrocarbon-soluble [tBuOCO]ZrCH2Ph(THF)2 (5). NMR spectroscopic measurements indicate a C2v-symmetric molecule that is isostructural with 4-PMe3. Addition of the larger phosphine PMe2Ph to 2 provides the corresponding mono-PMe2Ph complex in solution, but a small amount of the bis-diphenolate [tBuOCHO]2Zr (6) also forms. Complex 6 was independently synthesized by treating Zr(CH2Ph)4 with 2 equiv of 1. When 2 equiv of pyridine (py) is added to 2, the intermediate [tBuOCHO]ZrCH2Ph(η2−C5H4N)py (7) results from pyridine o-C−H bond activation. After 48 h, complex 7 releases another 1 equiv of toluene by activation of the pincer Cipso−H bond to produce the trianionic pincer complex [tBuOCO]Zr(η2-C5H4N)(py)2 (8). Multinuclear and 2D NMR spectroscopic experiments and combustion analysis support the molecular assignment of 8. Addition of α-picoline to 2 provides different results compared to py. Initially, the α-picoline adduct [tBuOCHO]Zr(CH2Ph)2(α-picoline) (9) forms. Addition of another 1 equiv of α-picoline provides the mixed η2(N,C)-6-Me-pyridyl)/η2(N,C-CH2)-pyrid-2-yl complex [tBuOCHO]Zr(η2(N,C)-6-Me-pyridyl)(η2(N,C-CH2)-pyrid-2-yl) (10)

Di-, Tri-, Tetra-, and Hexanuclear Copper(II) Mono-organophosphates: Structure and Nuclearity Dependence on the Choice of Phosphorus Substituents and Auxiliary N-Donor Ligands

Reactions of 2,6-dimethylphenyl phosphate (dmppH2) and 2,6-diisopropylphenyl phosphate (dippH2) with copper(II) precursors have been investigated in the presence of auxiliary N-donor ligands, and new structural types of copper phosphates have been isolated. Copper acetate reacts with dmppH2 in the presence of either 3,5-di-tert-butyl pyrazole (dbpz) or 3,5-dimethyl pyrazole (dmpz), leading to the isolation of tetrameric complex [Cu(dmpp)(dbpz)]4 1 and hexanuclear cage complex [Cu6(PO4)(dmpp)3(OAc)3(dmpz)9] 2, respectively. Whereas compound 1 is a cubane-shaped cluster whose Cu4O12P4 core resembles the double-4-ring (D4R) zeolite SBU, compound 2 is a novel hexanuclear copper complex with an unprecedented structure in metal phosphate chemistry. Use of bulkier dippH2 in the above reactions, however, yielded metal-free acid−base complexes [(dippH)(dbpz)(dbpzH)] 3 and [(dippH)(dmpz)(dmpzH)] 4, respectively. The reactions carried out between copper acetate and dmppH2 or dippH2 in the presence of chelating ligand 1,10-phenanthroline produced structurally similar dimeric copper phosphates [Cu(phen)(dmpp)(CH3OH)]2·2CH3OH 5 and [Cu(phen)(dipp)(CH3OH)]2·2CH3OH 6 with a S4R SBU core. Changing the copper source to [Cu2(bpy)2(OAc)(OH)(H2O)]·2ClO4 and carrying out reactions both with dippH2 and with dmppH2 result in the formation of trinuclear copper phosphates [Cu3(bpy)3(dmpp)2(CH3OH)3]·2ClO4·2CH3OH 7 and [Cu3(bpy)3(dipp)2(CH3OH)3]·2ClO4·2CH3OH 8. The three copper ions in 7 and 8 are held together by two bridging phosphate ligands to produce a tricyclic derivative whose core resembles the 4=1 SBU of zeolites. Compounds 1−8 have been characterized by elemental analysis and IR, absorption, emission, and EPR spectroscopic techniques. The crystal structures of compounds 1, 2, 4, 5, 6, and 8 have also been established by single-crystal X-ray diffraction studies

Synthesis and Characterization of Tungsten(VI) Alkylidene Complexes Supported by an [OCO]³⁻ Trianionic Pincer Ligand: Progress towards the [^<i>t</i>BuOCO]WCC(CH₃)₃ Fragment

The synthesis and characterization of trianionic [tBuOCO]3− pincer-supported tungsten alkylidene and alkylidyne complexes are described. The reaction of an equimolar ratio of (tBuO)3WCC(CH3)3 (where tBuO = tert-butoxide) with [tBuOCO]H3 (9) and 2,6-diisopropylphenol affords the alkylidene [tBuOCO]WCHC(CH3)3(O-2,6-C6H3-iPr2) (10), with a five-coordinate tungsten center that adopts a distorted square-pyramidal geometry. Treatment of (Np)3WCC(CH3)3 (11) with 9 provides an equilibrium mixture of the two isomeric alkylidenes with the general formula [(tBuOCO)WCHC(CH3)3(μ-tBuOCHO)WCHC(CH3)3(tBuOCO)] (12kin and 12therm). Single crystals of the two isomers cocrystallize and were amenable to X-ray diffraction studies, which revealed subtle differences in their molecular structures, most notably the orientation of the bridging ligand. The complexes are each comprised of two square-pyramidal tungsten ions linked by the diphenolate form of the OCO ligand. Isomer 12kin could not be isolated independently; however, adding PMe2Ph to the metalation between 11 and 9 provided 12therm exclusively, thus enabling a full set of characterization techniques including 2-D NMR spectroscopy. Salt metathesis between [tBuOCHO]K2(THF)2 (15) and (DME)Cl3WCC(CH3)3 (16) in diethyl ether produces the alkylidyne (tBuOCHO)WCC(CH3)3Cl (17) as the major product along with 12kin and other unidentified decomposition products. As a consequence, characterization of 17 was limited to 1H NMR spectroscopy and mass spectrometry

Synthesis and Characterization of Tungsten(VI) Alkylidene Complexes Supported by an [OCO]³⁻ Trianionic Pincer Ligand: Progress towards the [^<i>t</i>BuOCO]WCC(CH₃)₃ Fragment

The synthesis and characterization of trianionic [tBuOCO]3− pincer-supported tungsten alkylidene and alkylidyne complexes are described. The reaction of an equimolar ratio of (tBuO)3WCC(CH3)3 (where tBuO = tert-butoxide) with [tBuOCO]H3 (9) and 2,6-diisopropylphenol affords the alkylidene [tBuOCO]WCHC(CH3)3(O-2,6-C6H3-iPr2) (10), with a five-coordinate tungsten center that adopts a distorted square-pyramidal geometry. Treatment of (Np)3WCC(CH3)3 (11) with 9 provides an equilibrium mixture of the two isomeric alkylidenes with the general formula [(tBuOCO)WCHC(CH3)3(μ-tBuOCHO)WCHC(CH3)3(tBuOCO)] (12kin and 12therm). Single crystals of the two isomers cocrystallize and were amenable to X-ray diffraction studies, which revealed subtle differences in their molecular structures, most notably the orientation of the bridging ligand. The complexes are each comprised of two square-pyramidal tungsten ions linked by the diphenolate form of the OCO ligand. Isomer 12kin could not be isolated independently; however, adding PMe2Ph to the metalation between 11 and 9 provided 12therm exclusively, thus enabling a full set of characterization techniques including 2-D NMR spectroscopy. Salt metathesis between [tBuOCHO]K2(THF)2 (15) and (DME)Cl3WCC(CH3)3 (16) in diethyl ether produces the alkylidyne (tBuOCHO)WCC(CH3)3Cl (17) as the major product along with 12kin and other unidentified decomposition products. As a consequence, characterization of 17 was limited to 1H NMR spectroscopy and mass spectrometry