Single crystal X-ray diffraction, magnetic and 57Fe Mӧssbauer spectroscopic studies of a new iron(II)-based spin transition complex - [Fe(3-bpp)2](CF3COO)2 (bpp = 2,6-bis(pyrazol-3-yl)pyridine) are reported. The complex exhibits an incomplete thermal...

<p>Samples of vanadium- and -chromium doped TiO₂-anatas have been conducted antibacterial activity against the bacteria<em> Escherichia coli </em>(<em>E. Coli</em>). The minimum kill concentration (MBC) against the bacteria of <em>E. Coli</em> is determined  by liquid dilution method. The antibacterial activity test of 0; 2.3; 3.3; 4.9% wt. vanadium doped TiO₂-anatas and 0; 1.1; 3.9; 4.4% wt. chromium doped TiO₂-anatas have been performed against bacteria of <em>E. Coli</em> in the absence of light (dark). The test results indicate that the presence of 3.3 and 4.9 in %wt. vanadium-TiO₂-anatas are able to inhibit the growth of bacteria <em>E. Coli</em>, contrary all chromium doped TiO₂-anatas are not able to inhibit the growth of bacteria of <em>E. Coli</em>.</p>

Chromium-containing silicalite-1, designed CrS-1, was synthesized by the hydrothermal method and characterized by XRD and FTIR techniques. The objectives of the research are to study the synthesis of CrS-1 and investigate the effect of crystallization temperatures and times toward its character. All samples of CrS-1 crystallized in orthorhombic structure and Pnma space group. The phase observed in the XRD patterns of CrS-1 synthesized from 150 to 190 oC for 11 days showed only MFI-type phase. The CrS-1 prepared under static condition for 1 day at 150 oC indicated -SiO2 phase, on the contrary, the samples conditioned for 2 to 8 days at 150 oC are only MFI phase.   Keywords: Crystallization, synthesis, chromium silicate CrS-1, incorporation.

Intercalation of oligomeric chromium(III) polycation species in layered tetratitanates was prepared by three steps: 1) ion-exchange of H+ for K+ in potasium tetratitanates, 2) intercalation of n-alchylamine (n-propylamine, n-butylamine, n-amylamine, and n-hexylamine) compounds in layered hydrogen tetratitanates by adding an aqueous solution of  5M n-alchylamine to  hydogen titanates with stiring at room temperature,  and 3) intercalation of oligomeric chromium(III) polycation species by mixing butylamine-intercalated tetratitanates with an aqueous solution of CrCl3.6H2O at pH various. The procedure was carried out by Chimie Douce method. The results showed that all of n-alchylamine-intercalated tetratitanates crystallize on monoclinic crystal system with the Bravais lattice C. The hight intensity of the first peaks (200)  indicated that butylamine and amylamine-intercalated tetratitanates have a remarkably high crystallinity without impurities phase. The interlayered distance (d) and  the lattice parameter projected along a increase with increasing the amount of C-atoms in n-alchylamine. At pH=1.3, [CrCl(H2O)5]2+ or [CrCl2(H2O)4]+ species was pillared more efective in layered tetratitanates than [Cr(H2O)6]3+ spesies and just one spesies, Cr(H2O)6]3+ at  pH=1.7. On the contrary, [Cr(OH)(H2O)5]2+ or [Cr(OH)2(H2O)4]+ was  intercalated more effevtive than [Cr(H2O)6]3+ species  at pH=5.3.   Keywords: tetratitanates, intercalation, oligomeric chromium(III) species, Chimie Douce.

AbstrakTitanium dioksida (TiO 2 ) merupakan semikonduktor yang memiliki fungsi sebagai fotokatalis, sel surya, anti bakteri, anti polutan, dan anti buram. Salah satu cara untuk meningkatkan aktifitas fungsional TiO 2 dengan menggeser daerah aktifitas atau energi celah pita (E g ) dari sinar ultra violet (UV) ke daerah sinar tampak melalui penambahan zat pensensitif TiO 2 . Pada penelitian ini, perak klorida (AgCl) digunakan sebagai zat pensensitif TiO 2 . Tujuan penelitianini untuk mengetahui pengaruh variasi perbandingan mol awal [Ti 8 O 12 (H 2 O) 24 ] 8 .Cl 8 .HCl.7H 2 O dengan AgNO 3 terhadap sifat-sifat fisik TiO 2 tersensitifkan AgCl (TiO 2 @AgCl) yang disintesis dengan metode pengendapan basah dalam suasana asam. Variasi perbandingan awal yang digunakan yaitu perbandingan mol [Ti 8 O 12 (H 2 O) 24 ] 8 .Cl 8 .HCl.7H 2 O :mol AgNO 3 sebesar 1:9, 1:10, 1:11, 1:12, dan 1:13 yang dilarutkan dalam pelarut etanol (total pelarut 37.5 mL). Sampel padat TiO 2 @AgCl dihasilkan dengan metode pengendapan basah dalam kondisi asam melalui pengontrolan asam HNO 3 pada pH~1. Sampel dihasilkan dari penguapan filtrat yang bebas dari endapan AgCl, hingga volume yang didapat setengah dari volume awal. Sampel TiO 2 @AgCl dikarakterisasi dengan berbagai instrumen: Difraktometer Sinar-X (XRD), Scanning Electron Microscopy-Electron Dispersive X-Ray Analyzer (SEM-EDAX), dan Spektrofotometer UV-Vis Diffuse Reflectance. Hasil penelitian menunjukkan semua sampel TiO 2 @AgCl berisi 1 fasa nanopartikel (nanokristalit) TiO 2 dan 3 fasa kristal yaitu rutil, anatas, dan AgCl.TiO 2 @AgCl memiliki bentuk morfologi berupa mikrosferik dengan ukuran berkisar 0.5-1 μm. Berdasarkan hasil analisis dengan spektrofotometer UV-Vis Diffuse Reflectance menunjukkan semua sampel TiO 2 @AgCl mengabsorbsi sinar ultra violet (UV) dengan E g sebesar 2.87-3.89 eV, dan sinar tampak dengan E g sebesar 1.60-2.40 eV.Kata kunci: Titanium dioksida, suasana asam, sifat-sifat fisik, metode pengendapan kimia. AbstractTitanium dioxide (TiO 2 ) is a semiconductor that can be applied in the field of photocatalyst, solar cell, antibacterial, anti-pollutants, and anti-fogging. The functional activity of TiO 2 can be increased by shifting the activity area from ultraviolet (UV) to visible through the addition of sensitizer. In this research, silver chloride (AgCl) was used as a sensitizer The objective of the research is to study the effect of the initial mole comparison of [Ti 8 O 12 (H 2 O) 24 ] 8 .Cl 8 .HCl.7H 2 O and AgNO 3 on the physical properties of AgCl-sensitized TiO 2 (TiO 2 @AgCl). All TiO 2 @AgCl were synthesized using the wet chemical precipitation method under acidic conditions by the addition of a concentrated HNO 3 with pH ~ 1. The initial comparison variation used was the mole ratio of [Ti 8 O 12 (H 2 O) 24 ] 8 .Cl 8 .HCl.7H