scholarly journals Polyoxometalate clusters in minerals: review and complexity analysis

2020 ◽  
Vol 76 (4) ◽  
pp. 618-629 ◽  
Author(s):  
Sergey V. Krivovichev
Keyword(s):  
Complexity Analysis ◽  
Structural Complexity ◽  
Synthetic Compounds ◽  
Metal Atoms ◽  
Different Types ◽  
Trigonal Prismatic Coordination ◽  
Cluster Geometry ◽  
Nanoscale Clusters ◽  
Metal Oxo Clusters ◽  
Trigonal Prismatic

Most research on polyoxometalates (POMs) has been devoted to synthetic compounds. However, recent mineralogical discoveries of POMs in mineral structures demonstrate their importance in geochemical systems. In total, 15 different types of POM nanoscale-size clusters in minerals are described herein, which occur in 42 different mineral species. The topological diversity of POM clusters in minerals is rather restricted compared to the multitude of moieties reported for synthetic compounds, but the lists of synthetic and natural POMs do not overlap completely. The metal–oxo clusters in the crystal structures of the vanarsite-group minerals ([As3+V4+ 2V5+ 10As5+ 6O51]7−), bouazzerite and whitecapsite ([M 3+ 3Fe7(AsO4)9O8–;n (OH) n ]), putnisite ([Cr3+ 8(OH)16(CO3)8]8−), and ewingite ([(UO2)24(CO3)30O4(OH)12(H2O)8]32−) contain metal–oxo clusters that have no close chemical or topological analogues in synthetic chemistry. The interesting feature of the POM cluster topologies in minerals is the presence of unusual coordination of metal atoms enforced by the topological restraints imposed upon the cluster geometry (the cubic coordination of Fe3+ and Ti4+ ions in arsmirandite and lehmannite, respectively, and the trigonal prismatic coordination of Fe3+ in bouazzerite and whitecapsite). Complexity analysis indicates that ewingite and morrisonite are the first and the second most structurally complex minerals known so far. The formation of nanoscale clusters can be viewed as one of the leading mechanisms of generating structural complexity in both minerals and synthetic inorganic crystalline compounds. The discovery of POM minerals is one of the specific landmarks of descriptive mineralogy and mineralogical crystallography of our time.

Aquabis(4-formylbenzoato)-κ2 O,O′;κO-(1,10-phenanthroline-κ2 N,N′)cadmium(II)

2007 ◽  
Vol 63 (11) ◽  
pp. m2694-m2694 ◽  
Author(s):  
Zhao-Peng Deng ◽  
Shan Gao ◽  
Li-Hua Huo ◽  
Hui Zhao
Keyword(s):  
Hydrogen Bonding ◽  
Layer Structure ◽  
Title Complex ◽  
Coordination Geometry ◽  
Two Dimensional ◽  
Complex Molecules ◽  
Hydrogen Bonding Interactions ◽  
Trigonal Prismatic Coordination ◽  
Phenanthroline Ligand ◽  
Trigonal Prismatic

The CdII atom in the title complex, [Cd(C8H5O3)2(C12H8N2)(H2O)], is coordinated by three O atoms of two formylbenzoate ligands, two N atoms of a 1,10-phenanthroline ligand and one water molecule, giving rise to a trigonal–prismatic coordination geometry. Adjacent complex molecules are linked into a two-dimensional layer structure via hydrogen-bonding interactions.

Novel three-dimensional coordination polymers of lanthanides with sulfate and oxydiacetic acid

2013 ◽  
Vol 69 (12) ◽  
pp. 1503-1508 ◽  
Author(s):  
Thazhe Kootteri Prasad ◽  
M. V. Rajasekharan
Keyword(s):  
Crystal Structure ◽  
Coordination Polymers ◽  
Three Dimensional ◽  
Lanthanide Oxides ◽  
Coordination Polyhedra ◽  
Hydrothermal Reactions ◽  
Lanthanide Cations ◽  
Trigonal Prismatic Coordination ◽  
Oxydiacetic Acid ◽  
Trigonal Prismatic

Three three-dimensional coordination polymers,viz.poly[[diaqua-μ4-oxydiacetato-di-μ4-sulfato-dipraseodymium(III)] hemihydrate], [Pr2(C4H4O5)(SO4)2(H2O)2]·0.5H2O, (I), poly[[diaquadi-μ3-oxydiacetato-μ3-sulfato-dineodymium(III)] 1.32-hydrate], [Nd2(C4H4O5)2(SO4)(H2O)2]·1.32H2O, (II), and poly[[diaquadi-μ3-oxydiacetato-μ3-sulfato-disamarium(III)] 1.32-hydrate], [Sm2(C4H4O5)2(SO4)(H2O)2]·1.32H2O, (III), were obtained by hydrothermal reactions of the respective lanthanide oxides and ZnSO4with oxydiacetic acid (odaH2). The Nd3+and Sm3+compounds form isomorphous crystal structures in which the lanthanide cations are nine-coordinate, having a tricapped trigonal prismatic coordination. The Pr3+compound has an entirely different crystal structure in which two types of coordination polyhedra are observed,viz.nine-coordinate (trigonal prism) and ten-coordinate (bicapped square antiprism). The sulfate anions show various coordination modes, one of which has only rarely been observed crystallographically to date.

Mossbauer studies in transition metal chemistry. III. Compounds of iron with some sulphur-containing Schiff base ligands

1974 ◽  
Vol 27 (11) ◽  
pp. 2307 ◽  
Author(s):  
M Bond ◽  
RL Martin ◽  
IAG Roos
Keyword(s):  
Schiff Base ◽  
Tridentate Ligand ◽  
Coordinate Structure ◽  
Schiff Base Ligands ◽  
Tridentate Ligands ◽  
Cubic Symmetry ◽  
Field Gradients ◽  
Metal Atoms ◽  
Different Types ◽  
Local Symmetries

M�ssbauer spectra are reported for a series of iron complexes with sulphur-containing Schiff base ligands. These tridentate ligands are based on the Schiff base formed by the condensation of dithiocarbazic acid and pyridine-2-carbaldehyde and form complexes with a metal-to-ligand ratio of 1 : 1 and 1 : 2. The M�ssbauer study confirms that most of these complexes contain iron(11) with examples of both high-and low-spin and one example of a spin crossover. Several iron(111) complexes were also studied. The quadrupole splittings show the anisotropy in bonding expected for metal atoms coordinated to different types of atoms within the same chelate ring. However, for some complexes the splittings are small, showing that low local symmetries need not produce large electric field gradients. In cases where it is applicable, the temperature dependence of the quadrupole splitting has been used to derive a splitting of the t2 and e orbitals produced by the non-cubic symmetry. For compounds of the form Fe(L)X2, where X is a halide and L the tridentate ligand, the Mossbauer results are best interpreted in terms of a five-coordinate structure rather than a six-coordinate bridged dimer.

Trigonal-prismatic coordination. Complexes of intermediate geometry

1970 ◽  
Vol 92 (21) ◽  
pp. 6365-6366 ◽  
Author(s):  
Everly B. Fleischer ◽  
A. E. Gebala ◽  
P. A. Tasker
Keyword(s):  
Coordination Complexes ◽  
Trigonal Prismatic Coordination ◽  
Trigonal Prismatic

Ternary Thallides REMgTl (Re = Y, La – Nd, Sm, Gd – Tm, Lu)

2005 ◽  
Vol 60 (3) ◽  
pp. 265-270 ◽  
Author(s):  
Rainer Kraft ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Rare Earth Metal ◽  
High Frequency ◽  
Three Dimensional ◽  
Earth Metal ◽  
X Ray ◽  
Sample Chamber ◽  
Trigonal Prismatic Coordination ◽  
Trigonal Prismatic

The rare earth metal (RE)-magnesium-thallides REMgTl (RE = Y, La-Nd, Sm, Gd-Tm, Lu) were prepared from the elements in sealed tantalum tubes in a water-cooled sample chamber of a high-frequency furnace. The thallides were characterized through their X-ray powder patterns. They crystallize with the hexagonal ZrNiAl type structure, space group P62m, with three formula units per cell. Four structures were refined from X-ray single crystal diffractometer data: α = 750.5(1), c = 459.85(8) pm, wR2 = 0.0491, 364 F2 values, 14 variables for YMgTl; α = 781.3(1), c = 477.84(8) pm, wR2 = 0.0640, BASF = 0.09(2), 425 F2 values, 15 variables for LaMgTl; α = 774.1(1), c = 473.75(7) pm, wR2 = 0.0405, 295 F2 values, 14 variables for CeMgTl; a = 760.3(1), c = 465.93(8) pm, wR2 = 0.0262, 287 F2 values, 14 variables for SmMgTl. The PrMgTl, NdMgTl, GdMgTl, TbMgTl, and DyMgTl structures have been analyzed using the Rietveld technique. The REMgTl structures contain two cystallographically independent thallium sites, both with tri-capped trigonal prismatic coordination: Tl1Mg3RE6 and Tl2Mg6RE3. Together the magnesium and thallium atoms form three-dimensional [MgTl] networks with Mg-Mg distances of 327 and Mg-Tl distances in the range 299 - 303 pm (data for CeMgTl)

Sr4Pt10In21 – the first representative of the Ho4Ni10In21 type with a divalent cation

2019 ◽  
Vol 74 (5) ◽  
pp. 443-449 ◽  
Author(s):  
Birgit Heying ◽  
Jutta Kösters ◽  
Rainer Pöttgen
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Glassy Carbon ◽  
Divalent Cation ◽  
High Frequency ◽  
Three Dimensional ◽  
X Ray ◽  
Trigonal Prismatic Coordination ◽  
Trigonal Prismatic

AbstractRod-shaped single crystals of Sr4Pt10In21were prepared from the elements in glassy-carbon crucibles in a high-frequency furnace. The structure of Sr4Pt10In21was refined from single-crystal X-ray diffractometer data:C2/m, Ho4Ni10Ga21type,a = 2322.62(7),b = 450.27(2),c = 1958.09(7) pm,β = 133.191(3)°,wR = 0.0464, 3200F2values and 107 variables. The three-dimensional [Pt10In21]δ−polyanionic network is stabilized through substantial Pt–In (269–313 pm Pt–In) and In–In (294–362 pm In–In) bonding. All platinum atoms have slightly distorted tri-capped trigonal prismatic coordination and the two crystallographically independent strontium atoms are located in penta-capped pentagonal prisms.

Occurrence and relative abundance of mosquitoes in stormwater retention facilities in North Carolina, USA

2006 ◽  
Vol 54 (6-7) ◽  
pp. 315-321 ◽  
Author(s):  
W.F. Hunt ◽  
C.S. Apperson ◽  
S.G. Kennedy ◽  
B.A. Harrison ◽  
W.G. Lord
Keyword(s):  
North Carolina ◽  
Relative Abundance ◽  
Seasonal Changes ◽  
Stormwater Management ◽  
Biological Diversity ◽  
Mosquito Species ◽  
Structural Complexity ◽  
Different Types ◽  
Retention Structures ◽  
Stormwater Retention

Throughout the 2004 mosquito season, 52 stormwater retention facilities were sampled to characterize the seasonal occurrence and relative abundance of mosquito species in relation to the structural complexity and biological diversity of the facilities. The three different types of facilities included standard wet ponds (n=20), innovative ponds (n=14), and wetland ponds (n=18). All retention structures were sampled at the beginning, middle and end of the mosquito season so that seasonal changes in mosquito production could be characterized. Overall samplings, mosquitoes were collected from 34% of the retention structures. Fourteen species representing 7 genera were collected, but only 5 species (Culex erraticus, Cx. territans, Anophelesquadrimaculatus, An. punctipennis and Uranotaenia sapphirina) were commonly collected in all three types of stormwater management facilities. In general, the seasonal prevalence and relative abundance of mosquito species did not vary among three types of retention structures. A significant association (P<0.01) between the presence of mosquito larvae or pupae and the absence of mosquitofish was found for innovative and wetland stormwater retention facilities but not for standard retention facilities (P>0.05).

Sign in / Sign up

Export Citation Format

Share Document