Growth morphology of crystals from kinetic and geometric perspective

The growth morphology of crystals is analysed from macroscopic point of view and the recent developments in this field are surveyed. In particular, it is shown that, for specific geometry characterized by interfacial angles a given face can increase in size for a very wide range of relative growth rates and need not be the slow‐growing face. Even growing faster than the neighbouring faces, such a face can increase in its size. However, there are other faces with other specific geometry, which can decrease the size growing more slowly than one of the neighbouring faces. If the growth time is sufficiently long, such a face may disappear and not be represented in the final crystal morphology. In the present survey the concepts given earlier [5] are extended. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Crystal structure of 2,4,6-trinitropyridine and its N-oxide

The structures of 2,4,6-trinitropyridine (TNPy) and its N-oxide were determined by X-ray single crystal diffraction. TNPy and 2,4,6-trinitropyridine-1-oxide (TNPyO) crystallize in space groupPbcn andPnma, respectively. The crystallographic parameters are as follows: TNPy,a = 28.573(6) Å,b = 9.7394(19) Å, andc = 8.7566(18) Å, α = β = γ = 90^°, μ = 0.164 mm^?1,V = 2436.8(8) ų,z = 12,Dx = 1.751 mg/mm³,F(000) = 1296,T = 293(2) K, 1.43^°≤ θ≤ 27.40^°, the finalR factor:R ₁ = 0.0574,wR ₂ = 0.1337. TNPyO,a = 9.6272(19) Å,b = 14.128(3) Å, andc = 5.9943(12) Å, α = β = γ = 90^°, μ = 0.179 mm^?1,V = 815.3(3)ų,z = 4,Dx = 1.875 mg/mm³,F(000) = 464,T = 293(2) K, 2.88^°≤ θ≤ 27.44^°, the finalR factor:R ₁ = 0.0497,wR ₂ = 0.1515.     

Crystal structure and thermal analysis of 1,5-diammonium-2-methyl pentane sulfate monohydrate

Chemical preparation, x-ray single crystal, and thermal analysis of C₆H₁₈N₂SO₄·H₂O (denoted DMPS) are described. The compound crystallizes in the triclinic system with P space group. Its unit cell dimensions are a = 5.826(1) Å, b = 10.014(1) Å, c = 11.221(1) Å, = 66.716(1)°, = 84.395(1)°, = 83.759(1)°, V = 596.7(1) ų, and Z = 2. The DMPS structure is built up from inorganic chains parallel to the a axis and linked via O(W)-H···O hydrogen bonds. These chains are interconnected by organic groups. Thermal analysis reveals the presence of one water molecule in the structure and shows a reversible weak phase transition.     

Preparation of copper aluminum borate whiskers via flux method

Single‐crystal and uniform copper aluminum borate whiskers have been synthesized by heating a mixture of boric acid, copper sulfate and aluminum sulfate with potassium sulfate as flux at 870 °C for 4 h. The synthesized whiskers exhibit a well‐crystallized, one‐dimensional structure with diameters ranging from 100 nm to 5 μm, lengths from 5 to 100 μm. Heating temperature and flux addition affect the aspect ratio and morphology of the copper aluminum borate whiskers. A possible growth mechanism of the whiskers is proposed. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Size and morphology controlled synthesis of barium sulfate

In this work submicron barium sulfate (BaSO₄) particles were synthesized successfully by chemical precipitation technique. We focused on the effects of pH and additives on the size and morphology of BaSO₄ crystals. Polyacrylic acid, polyvinyl sulfonic acid and ethylenediaminetetraacetic acid were used as crystal growth modifiers. BaSO₄ crystals were characterized using scanning electron microscopy, X‐ray diffraction, and Fourier transform infrared resonance techniques. The results show that the submicron BaSO₄ particles have been synthesized successfully and the particle size of the barium sulfate was effectively controlled under the experimental conditions. Experimental studies revealed that the additive concentration and pH had great effect on the morphology and size of barium sulfate.     

Crystal structure of phenyl-substituted cyclopentenes

The crystal structures of two stereoisomers of tetraphenyl- and pentaphenyl-substituted cyclopentenes 1 and 2 have been determined by X-ray analysis. An envelope conformation ¹E has been ascertained for the cis isomer 1a, whereas the cis, cis isomer 2a, which crystallizes in two different space groups, P1¯ and P2₁/n, displays a twisted ²T₁ conformation. The phenyl substituents are all tilted with respect to the cyclopentene ring in both structures. Compound 1a crystallizes in the space group P2₁/a with a = 18.553(3), b = 6.006(2), c = 19.355(5), = 102.67(4)°, and V = 2104.2(g) ų for Z = 4; compound 2a ^I crystallizes in P2₁/n with a = 10.064(2), b = 20.756(5), c = 12.245(3) Å, = 95.21(2)°, and V = 2547(1) ų for Z = 4; compound 2aII crystallizes in P1¯ with a = 10.117(3), b = 11.750(2), c = 12.359(2) Å, = 111.25(2), = 94.84(2), = 108.78(2)°, and V = 1262.3(6) ų for Z = 2.     

Crystal structure of a novel bis(guanidiniums) compound incorporated by sulfate anion

Crystal structure of a novel bis(guanidiniums) compound 1 by sulfate anion and water, C₁₁H₂₀N₆OSO₄H₂O, was measured by X-ray crystallographic analysis with an imaging plate method. It possesses space group P2₁/c, with a = 7.6433(15), b = 19.447(4), c = 12.115(2) Å, = 107.81(3)°, and _calc = 1.420 mg/m³ for Z = 4. Crystal data indicate that the architecture network is formed through hydrogen bonds, electrostatic interactions, and arene–arene stacking interaction among the bis(guanidiniums) compound, the sulfate anion and water molecule.     

Crystal growth and structure of pure and rare-earth doped barium sodium niobate (BNN)

Through the exploitation of the corresponding ternary phase diagram, the barium sodium niobate (BNN) crystal growth by several techniques: Czochralski, Laser Heated Pedestal Growth and Micro-Pulling Down is surveyed. It is pointed out that the fiber crystal growth contributed to obtain important advances on the crystal structure, doping by rare-earth ions and growing behavior leading to what can be considered as an attractive new material. The further growth of high optical quality bulk crystals could now lead to the commercial development of this material with outstanding non-linear optical properties.     

Crystal structure of trismorpholino phosphiniminocyclotrithiazene

The title compound (OC₄H₈N)₃P=N–S₃N₃ crystallizes in a monoclinic crystal system with unit cell parameters a = 8.9996(3), b = 17.2895(7), and c = 12.3648(9) Å, = 90.63(5)°, Z = 4, and space group P2₁/n. Strikingly the exocylic S1–N4 bond length is 1.545(3) ÅR and is accompanied by the largest angle at P–N4–S1 as 131.2(2)°. The tricoordinated sulfur atom of the cyclotrithiazene ring deviates from the mean plane of other five atoms by 0.654(1) Å.     

Crystal structure and physical properties of a ruthenium(II) bipyridine dimethylsulfoxide complex

The complex [Ru(bpy)₂(DMSO)C1]PF₆, where bpy is 2,2-bipyridine and DMSO is dimethylsulfoxide, crystallizes in the triclinic space group P1¯ (#2) with a = 8.873 (2), b = 12.805 (4), c = 12.864 (4) Å, = 97.76(3), = 106.45(2), = 107.88(2); Z = 2, and d _calc = 1.75 mg/m³. The coordination geometry is that of a distorted octahedron with a cis –RuN₄SCl arrangement of coordinating atoms. The four Ru—N distances to the bpy ligands are 2.082(5), 2.092(4), 2.044(4), and 2.078(5) Å. The Ru—Cl distance is 2.421(2) Å and the Ru—S distance to DMSO is 2.260(1) Å. The Ru—N bond distance trans to Cl is the shortest; the Ru—N bond distance trans to S is the longest. The complex is oxidized and reduced reversibly at 1.13 and –1.37 V vs. SSCE, respectively. It displays electronic absorptions at 515, 480 (1.5 × 10⁴), 342 (1.5 × 10⁴), 292 (1.2 × 10⁵), and 240 nm (6.2 × 10⁴) and has a broad emission band centered at 607 nm at 77 K in a 4:1 ethanol/methanol glass. The emission lifetime at room temperature is less than the pulse width of the laser, < 20 ns.     

Crystal and molecular structure of iso-grayanotoxin II

The crystal and molecular structure of a grayanotoxin derivative, iso-grayanotoxin II, is presented. The crystal is orthorhombic, space group . The molecule is based on a tetracyclic structure consisting of two five-membered, one six-membered, and one seven-membered rings with various conformations.     

Crystal structure of nimbin

The crystal structure of nimbin has been determined. The crystals are orthorhombic, space groupP2₁2₁2₁ witha=6.790(2),b=14.875(4),c=27.160(8) Å andZ=4. The packing of the molecules in the lattice is due to C?H…O type of hydrogen bonds.     

Crystal structure, thermal analysis, and IR spectrometric investigation of bis(tert-butylammonium) sulfate

Chemical preparation, X-ray single crystal, thermal analysis, and IR spectrometric investigation of (C₄H₁₂N)₂SO₄, denoted tBAS, are described. The compound crystallizes in the monoclinic system with C2/c space group. Its unit cell dimensions are a = 11.1585(5) Å, b = 6.2148(4) Å, c = 20.070(1) Å, = 102.004(4)°, V = 1361.4(1) ų, and Z = 4. The crystal structure of tBAS can be described as a typical thick layered organization built by all the components of the structure and centered by planes z = 1/4 and 3/4. Connection in these layers are established by N—H···O hydrogen bonds. Thermal analysis shows a reversible weak phase transition.     

Crystal structure and intermolecular coordination behavior of a porphyrin bearing a hydroquinone receptor, meso-mono(hydroquinonyl) triphenylporphyrinatozinc

The structure of a porphyrin bearing a hydroquinone receptor unit, meso-mono(hydroquinonyl)triphenylporphyrinatozinc (1), is reported. The compound crystallizes from benzene in the monoclinic space group P2₁/c(#14) with a = 10.896(2) Å, b = 15.674(4) Å, c = 12.564(3) Å, = 102.04(2)° and d _calc= 1.368 g/cm³ for Z = 2. The unit cell has two porphyrins and four benzene solvates. The structural study reveals no self-assembled aggregates due to intermolecular coordination of the hydroxy groups of the hydroquinone to the zinc ion in the porphyrin cavity, an observation that agrees with the results of ¹H NMR studies performed in benzene-d₆ solutions. On the contrary, the ¹H NMR results in CDCl₃ indicate the existence of self-assembled aggregates.     

Two CrIII containing metal‐1‐hydroxyethylidenediphosphonate compounds: Synthesis,structure, and morphology

Two novel layered Cr^III containing metal‐hedp compounds, Na₂₀AlCr^III[CH₃C(O)P₂O₆]₆·O₃·(H₂O)₂₆·(H₃O)₁₀ (CH₃ CH₂ OH) and Na₆Cr^III[CH₃C(OH)P₂O₆]₃·(H₂O)₂₁(H₃O)₃ (designated as DLES‐AlCr and DLES‐Cr^III respectively), were hydrothermally synthesized. Their structures were determined by single‐crystal X‐ray diffraction. The two crystals are isostructural with propeller‐like chiral motifs and hexagonal rings along [001]. DLES‐AlCr crystal exhibits interesting hollow tubular hexagonal morphology, while DLES‐Cr crystal possesses solid hexagonal morphology. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

结晶生长的化学键合理论

针对一般晶体的生长过程,在测定相应溶液(熔体)组成结构的基础上,我们引入了晶体生长过渡相区的概念,并采用键价模型来衡量生长过程中发生变化的化学键的键强度。过饱和溶液(熔体)中的生长单元经过生长过渡相区时,依据彼此之间弱的化学键合作用来微调其内部强的化学键,并以单个生长单元或者生长单元的简单连接体的形式键合进入晶格。在整个结晶生长过程中,生长单元之间弱的键合作用对整个结晶过程(生长速度、晶相的形成)起着决定性作用;同时,中等强度的化学键在生长过渡相区中的变化情况对晶体的最终形貌具有重要影响。     

Crystal structure, thermal analysis, and IR spectrometric investigation of 1,2-diammonium-2-methyl propane sulfate monohydrate

Chemical preparation, X-ray single crystal, thermal analysis, and IR spectrometric investigation of C₄H₁₄N₂SO₄·H₂O (denoted DAMPS) are described. DAMPS crystallizes in the orthorhombic system with P2₁2₁2₁ space group, a = 9.2726(4) Å, b = 9.5227(2) Å, c = 10.3807(4) Å, V = 916.62(6) ų, and Z = 4. The DAMPS structure is built up from inorganic chains parallel to the b axis and linked via Ow–H···O hydrogen bonds. These chains are interconnected by organic groups so as to build a three-dimensional arrangement.     

Crystal and molecular structure of augustamine

The crystal and molecular structure of augustamine (1), C₁₇H₁₉NO₄ an amaryllidaceae alkaloid of the tazettine group has been determined by direct methods from single crystal x-ray diffractometer data and refined by full-matrix least squares. The alkaloid (1) crystallizes in the space group P2₁2₁2₁, with cell parameters: a = 7.833(8) b = 11.08(2) å, c = 16.69(6) Å, Z = 4, D_c = 1.381 g/cm^–3, R = 7.6% for 1115 observed reflections. The molecule, having a hexacyclic ring system, is very rigid with the ring B in a chair conformation. Molecular mechanics calculations have been made using MM3(2000) force field.     

Crystal structure of the tetranickel complex with Ipropanethiolate

The title complex [Ni₄(SPrⁱ)₈] was confirmed by single crystal X-ray crystal diffraction analysis. The crystals are monoclinic, space group P2/n with a = 12.760(3), b = 10.059(2), c = 14.484(3) Å, α = 90, β = 93.70(3), γ = 90°, V = 1855.3(6) ų, Z = 4, F(000) = 880, D_c = 1.496 g/cm³, μ = 2.463 mm^?1, the final R = 0.0352 and wR = 0.0580. A total of 18,588 reflections were collected, of which 4404 were independent (R_int = 0.0631). In the crystal packing diagram, intermolecular C—H···Ni hydrogen bonds stabilize the solid state of the title complex.     

配合物晶体MnHg(SCN)4的晶形分析

配合物晶体MnHg(SCN)4中维系晶体结构的化学键是-Mn-NCS-配位键.从MnHg(SCN)4晶体中配位键的分布特点出发,对属于点群4的单形四方四面体、四方柱和平行双面进行分析,确定晶形中不能出现平行双面{001}、四方柱{110},可以出现的单形为四方四面体{101}和{011}及四方柱{100},而且四方四面体{101}和{011}单形最发育.由结构分析得出的晶形特点与实际晶体晶形特点相符.