Penerapan Metode Pembelajaran Numbered Heads Together (Nht) Untuk Meningkatkan Motivasi Dan Hasil Belajar Kelarutan Dan Hasil Kali Kelarutan Kelas XI IPA 4 Sman 8 Surakarta Tahun Pelajaran 2012/2013

Tujuan penelitian ini adalah untuk meningkatkan (1) motivasi belajar kelarutan dan hasil kali kelarutan dan (2) hasil belajar kelarutan dan hasil kali kelarutan melalui penerapan metode pembelajaran Numbered Heads Together (NHT). Penelitian ini merupakan penelitian tindakan kelas (Classroom Action Research) yang dilaksanakan dalam dua siklus dimana setiap siklusnya terdiri atas empat tahapan, yaitu perencanaan, pelaksanaan, pengamatan, dan refleksi. Subjek penelitian adalah siswa kelas XI IPA 4 SMAN 8 Surakarta Tahun Pelajaran 2012/2013. Pengumpulan data dilakukan melalui pengamatan, wawancara, kajian dokumen, angket, dan tes. Data yang diperoleh divalidasi menggunakan teknik triangulasi sumber dan dianalisis menggunakan analisis deskriptif kualitatif yang mengacu pada Miles dan Huberman. Hasil penelitian menunjukkan capaian motivasi belajar pada siklus I dan siklus II masing-masing mencapai 58,33% dan 79,17%. Hasil belajar yang diukur pada aspek kognitif dan afektif menunjukkan pada siklus I mencapai 29,17% dan 62,5% serta pada siklus II mencapai 70,83% dan 83,33%. Simpulan penelitian ini adalah penerapan metode pembelajaran Numbered Heads Together (NHT) mampu meningkatkan (1) motivasi belajar kelarutan dan hasil kali kelarutan dan (2) hasil belajar kelarutan dan hasil kali kelarutan kelas XI IPA 4 SMAN 8 Surakarta

3-D Coordination Network Structures Constructed from [W₆S₈(CN)₆]^6- Anions

Octahedral molybdenum and tungsten clusters face-capped by chalcogens M6Q8 (M = Mo, W; Q = S, Se, Te) have drawn extensive attention because of the well-known molybdenum-based Chevrel phases. Water-soluble cyanide complexes of these clusters can be prepared by cluster excision from the solid-state compound Mo6Se8 or by ligand exchange from W6S8(4-tert-butylpyridine)6. The [W6S8(CN)6]6- cluster anion can, in turn, be used as a building block to construct 3-D extended coordination networks with transition metal cations M2+ (M = Mn, Fe, Co, Zn) as linking units. The novel 3-D structures were determined by X-ray crystallography to be two-fold interpenetrating distorted cubic networks of [M(II)(H2O)4]3[W6S8(CN)6]·xH2O (x ≈ 23; M = Mn, Fe, Co) or a rutile-like network of K2[Zn(H2O)2]2[W6S8(CN)6]·26H2O, both bridged through W−CN−M−NC−W linkages. The properties of the new network structures are investigated and factors relevant to the construction of network structures containing W6S8 clusters are discussed

3-D Coordination Network Structures Constructed from [W₆S₈(CN)₆]^6- Anions

Octahedral molybdenum and tungsten clusters face-capped by chalcogens M6Q8 (M = Mo, W; Q = S, Se, Te) have drawn extensive attention because of the well-known molybdenum-based Chevrel phases. Water-soluble cyanide complexes of these clusters can be prepared by cluster excision from the solid-state compound Mo6Se8 or by ligand exchange from W6S8(4-tert-butylpyridine)6. The [W6S8(CN)6]6- cluster anion can, in turn, be used as a building block to construct 3-D extended coordination networks with transition metal cations M2+ (M = Mn, Fe, Co, Zn) as linking units. The novel 3-D structures were determined by X-ray crystallography to be two-fold interpenetrating distorted cubic networks of [M(II)(H2O)4]3[W6S8(CN)6]·xH2O (x ≈ 23; M = Mn, Fe, Co) or a rutile-like network of K2[Zn(H2O)2]2[W6S8(CN)6]·26H2O, both bridged through W−CN−M−NC−W linkages. The properties of the new network structures are investigated and factors relevant to the construction of network structures containing W6S8 clusters are discussed

Ni₃Cr₂P₂Q₉ (Q = S, Se): New Quaternary Transition Metal Chalcogenides with a Unique Layered Structure

The new transition metal chalcogenides Ni3Cr2P2S9 and Ni3Cr2P2Se9 have been discovered and characterized. Single-crystal X-ray diffraction studies of the selenide reveal a new layered structure type (space group P63/m, a = 6.244(4) Å, c = 18.479(19) Å, Z = 2, R1 = 0.0235). Powder X-ray diffraction and electron microprobe analysis suggest that the sulfide is isostructural to the selenide and that a solid solution forms between them. The layers are composed of transition metal centered octahedra with chalcogenides at the vertices which are joined in pairs by face sharing along the c-direction. These units share edges to form honeycomb layers in the ab-plane with linear P−Ni−P units in the holes of the honeycomb nets. Transport properties measurements from 80−300 K on single crystals with compositions Ni3Cr2P2S9-xSex (x = 0, 3, 6) revealed activated behavior in electrical resistivity (Ea = 0.02−0.03 eV, ρ300K = 50−220 mΩ·cm) and positive values of the Seebeck coefficient (S300K = 80−225 μV/K), showing that these compounds behave like p-type semiconductors. Magnetization measurements on Ni3Cr2P2S9 single crystals from 5 to 400 K reveal antiferromagnetic interactions between the transition metal ions and an ordering transition near 105 K

Ni₃Cr₂P₂Q₉ (Q = S, Se): New Quaternary Transition Metal Chalcogenides with a Unique Layered Structure

The new transition metal chalcogenides Ni3Cr2P2S9 and Ni3Cr2P2Se9 have been discovered and characterized. Single-crystal X-ray diffraction studies of the selenide reveal a new layered structure type (space group P63/m, a = 6.244(4) Å, c = 18.479(19) Å, Z = 2, R1 = 0.0235). Powder X-ray diffraction and electron microprobe analysis suggest that the sulfide is isostructural to the selenide and that a solid solution forms between them. The layers are composed of transition metal centered octahedra with chalcogenides at the vertices which are joined in pairs by face sharing along the c-direction. These units share edges to form honeycomb layers in the ab-plane with linear P−Ni−P units in the holes of the honeycomb nets. Transport properties measurements from 80−300 K on single crystals with compositions Ni3Cr2P2S9-xSex (x = 0, 3, 6) revealed activated behavior in electrical resistivity (Ea = 0.02−0.03 eV, ρ300K = 50−220 mΩ·cm) and positive values of the Seebeck coefficient (S300K = 80−225 μV/K), showing that these compounds behave like p-type semiconductors. Magnetization measurements on Ni3Cr2P2S9 single crystals from 5 to 400 K reveal antiferromagnetic interactions between the transition metal ions and an ordering transition near 105 K

Synthesis and Characterization of Ba₃Bi_6.67Se₁₃ and Its Filled Variants Ba₃Bi₆PbSe₁₃ and Ba₃Bi₆SnSe₁₃

The three title compounds were synthesized at 710 °C and their structure type is isotypic to Sr4Bi6Se13 and β-K2Bi8Se13. The compounds crystallize in P21/m (Z = 2) with a = 17.2228(6) Å, b = 4.2729(1) Å, c = 18.4659(6) Å, β = 90.720(0)° for Ba3Bi6.67Se13; a = 17.2427(4) Å, b = 4.2736(1) Å, c = 18.4560(4) Å, β = 90.861(1)° for Ba3Bi6PbSe13; and a = 17.2498(5) Å, b = 4.2912(1) Å, c = 18.4590(5) Å, and β = 90.679(1)° for Ba3Bi6SnSe13. The coordination environments of Bi/Pb/Sn are distorted Se octahedra, while the coordination spheres of Ba are bi- or tricapped trigonal prisms. Transport measurements indicate that Ba3Bi6.67Se13 and Ba3Bi6PbSe13 are semiconducting

Synthesis and Characterization of Ba₃Bi_6.67Se₁₃ and Its Filled Variants Ba₃Bi₆PbSe₁₃ and Ba₃Bi₆SnSe₁₃

The three title compounds were synthesized at 710 °C and their structure type is isotypic to Sr4Bi6Se13 and β-K2Bi8Se13. The compounds crystallize in P21/m (Z = 2) with a = 17.2228(6) Å, b = 4.2729(1) Å, c = 18.4659(6) Å, β = 90.720(0)° for Ba3Bi6.67Se13; a = 17.2427(4) Å, b = 4.2736(1) Å, c = 18.4560(4) Å, β = 90.861(1)° for Ba3Bi6PbSe13; and a = 17.2498(5) Å, b = 4.2912(1) Å, c = 18.4590(5) Å, and β = 90.679(1)° for Ba3Bi6SnSe13. The coordination environments of Bi/Pb/Sn are distorted Se octahedra, while the coordination spheres of Ba are bi- or tricapped trigonal prisms. Transport measurements indicate that Ba3Bi6.67Se13 and Ba3Bi6PbSe13 are semiconducting

Synthesis and Structure of a New Quinary Sulfide Halide: LaCa₂GeS₄Cl₃

A new quinary rare earth sulfide−halide compound has been synthesized and its structure determined by single-crystal X-ray diffraction. LaCa2GeS4Cl3 crystallizes in the noncentrosymmetric hexagonal space group -P63mc (No. 186) with Z = 2, a = 9.731(1) Å, and c = 6.337(1) Å. Lanthanum and calcium are mixed on a pseudo-trigonal prismatic site, coordinated to three sulfur atoms on one triangular face and three chlorine atoms on the other. Isolated, slightly distorted tetrahedra of GeS4 are oriented with a tetrahedral 3-fold axis aligned along the crystallographic 3-fold rotation axis. Preliminary optical studies indicate that this material has a useful optical window extending approximately from 0.5 to 10 μm. Nonlinear optical activity of LaCa2GeS4Cl3 is demonstrated by the generation of green light when pumped with a 1.064 μm Nd:YAG laser

Ordered Intermetallic Pt–Sn Nanoparticles: Exploring Ordering Behavior across the Bulk Phase Diagram

Because the bulk phase diagram of Pt–Sn contains five different compounds (Pt₃Sn, PtSn, Pt₂Sn₃, PtSn₂, and PtSn₄) with very different congruent or incongruent melting points, we chose this system to investigate factors that influence the homogeneity and structure of intermetallic nanoparticles with different compositions prepared by the same solution phase co-reduction reaction. Pt and Sn chloride precursors were reduced by alkali metal borohydrides in tetrahydrofuran. Of the five compositions, only PtSn forms ordered intermetallic nanoparticles (average domain size of 4.3 nm) at room temperature. As-prepared Pt₃Sn nanoparticles adopt an alloy FCC structure and ordered into the cubic Cu₃Au structure at the unexpectedly low annealing temperature of 200 °C. Despite their low bulk incongruent melting temperatures, the tin-rich compositions (PtSn_<i>x</i>, where <i>x</i> = ³/₂, 2, or 4), by contrast, form highly disordered products at room temperature and require annealing at ≥200 °C for crystallization and ordering to be observed. Phases prepared from tin­(II) chloride exhibit co-reduction behavior different from that of tin­(IV) chloride, the latter requiring overall higher temperatures to produce similarly ordered particles. Spectroscopic studies indicate that this behavior may be due to the formation of Pt–Sn complexes in solution prior to the reduction when tin­(II) is used as a precursor, but not for tin­(IV), resulting in more consistent nucleation of the target stoichiometric phases. The process of crystallization by annealing is discussed

Ligand Substitution Reactions of W₆S₈L₆ with Tricyclohexylphosphine (L = 4-<i>tert</i>-Butylpyridine or <i>n</i>-Butylamine): ³¹P NMR and Structural Studies of W₆S₈(PCy₃)<i>_n</i>(4-<i>tert</i>-butylpyridine)₆_-<i>_n</i> (0 < <i>n</i> ≤ 6) Complexes

The substitution reactions by bulky tricyclohexylphosphine (PCy3) ligands on W6S8L6 (L = 4-tert-butylpyridine or n-butylamine) clusters were investigated to prepare clusters with mixed axial ligands for low-dimensional cluster linking. When 4−6 equiv of PCy3 are used to react with W6S8(4-tert-butylpyridine)6 (4) in THF, cis-W6S8(PCy3)4(4-tert-butylpyridine)2 (1) is preferentially formed. But when starting with W6S8(n-butylamine)6 (2), only W6S8(PCy3)6 (3) is produced with 6 equiv of PCy3. Other conditions with fewer equivalents of PCy3 led to mixtures of partially substituted complexes in the W6S8L6-n(PCy3)n (0 ≤ n ≤ 6, L = 4-tert-butylpyridine or n-butylamine) series. A significantly distorted structure for 1 helps to explain its preferential formation. 1H NMR spectra were collected for clusters 1 and 2 and 31P NMR spectra for 1 and W6S8(4-tert-butylpyridine)6-n(PCy3)n complexes. P−P coupling through P−W−W−P is reported for the first time in octahedral metal clusters and shown to be very useful in identifying nearly all the W6S8L6-n(PR3)n complexes and their stereoisomers in the mixtures even before individual species are isolated