Determination of the Uranium(VI) and ‐(IV) Species in Uranium Ores

The determination of the two species of uranium(VI and IV) present in 6 uranium ores was studied in relation to the chemical and mineralogical composition, humidity, and pH of the samples taken over from the mine. X‐ray diffraction studies, performed on the uranium ores in powder form allowed to establish their mineralogical composition. Thechemical analysis pointed out the presence, besides the two uranium species, of some microelements able to influence the U^VI/U^IV ratio in minerals and to leach out U^VI as uranyl ions from the corresponding minerals.     

Vaulted trans‐Bis(salicylaldiminato)platinum(II) Crystals: Heat‐Resistant,Chromatically Sensitive Platforms for Solid‐State Phosphorescence at Ambient Temperature

The synthesis, structure, and solid‐state emission of vaulted trans‐bis(salicylaldiminato)platinum(II) complexes are described. A series of polymethylene ( 1 : n=8; 2 : n=9; 3 : n=10; 4 : n=11; 5 : n=12; 6 : n=13) and polyoxyethylene ( 7 : m=2; 8 : m=3; 9 : m=4) vaulted complexes (R=H ( a ), 3‐MeO ( b ), 4‐MeO ( c ), 5‐MeO ( d ), 6‐MeO ( e ), 4‐CF₃O ( f ), 5‐CF₃O ( g )) was prepared by treating [PtCl₂(CH₃CN)₂] with the corresponding N,N′‐bis(salicylidene)‐1,ω‐alkanediamines. The trans coordination, vaulted structures, and the crystal packing of 1 – 9 have been unequivocally established from X‐ray diffraction studies. Unpredictable, structure‐dependent phosphorescent emission has been observed for crystals of the complexes under UV excitation at ambient temperature, whereas these complexes are entirely nonemissive in the solution state under the same conditions. The long‐linked complex crystals 4 – 6 , 8 , and 9 exhibit intense emission (Φ_77K=0.22–0.88) at 77 K, whereas short‐linked complexes 1 – 3 and 7 are non‐ or slightly emissive at the same temperature (Φ_77K<0.01–0.18). At 298 K, some of the long‐linked crystals, 4 a , 4 b , 5 c , 5 e , 6 c , 6 e , and 9 b , completely lose their high‐emission properties with elevation of the temperature (Φ_298K<0.01–0.02), whereas the other long‐linked crystals, 5 a , 6 a , 9 a , and 9 d , exhibit high heat resistance towards emission decay with increasing temperature (Φ_298K=0.21–0.38). Chromogenic control of solid‐state emission over the range of 98 nm can be performed simply by introducing MeO groups at different positions on the aromatic rings. Orange, yellow‐green, red, and yellow emissions are observed in the glass and crystalline state upon 3‐, 4‐, 5‐, and 6‐MeO substitution, respectively, whereas those with CF₃O substituents have orange emission, irrespective of the substitution position. DFT calculations (B3LYP/6‐31G*, LanL2DZ) showed that such chromatic variation is ascribed to the position‐specific influence of the substituents on the highest‐occupied molecular orbital (HOMO) and lowest‐unoccupied molecular orbital (LUMO) levels of the trans‐bis(salicylaldiminato)platinum(II) platform. The solid‐state emission and its heat resistance have been discussed on the basis of X‐ray diffraction studies. The planarity of the trans‐coordination sites is strongly correlated to the solid‐state emission intensities of crystals 1 – 9 at lower temperatures. The specific heat‐resistance properties shown exclusively by the 5 a , 6 a , 9 a , and 9 d crystals are due to their strong three‐dimensional hydrogen‐bonding interactions and/or Pt???Pt contacts, whereas heat‐quenchable crystals 4 a , 4 b , 5 c , 5 e , 6 c , 6 e , and 9 b are poorly bound with limited interactions, such as non‐, one‐, or two‐dimensional hydrogen‐bonding networks. These results lead to the conclusion that Pt???Pt contacts are an important factor in the heat resistance of solid‐state phosphorescence at ambient temperature, although the role of Pt???Pt contacts can be substituted by only higher‐ordered hydrogen‐bonding fixation.     

Crystallographic report: Ethyltriphenyltin(IV), Et(Ph)3Sn

The crystal lattice of the title compound comprises isolated molecules. The coordination polyhedron is a slightly distorted tetrahedron with C–Sn–C bond angles ranging from 106.62(17)° to 113.9(3)°. Copyright © 2004 John Wiley & Sons, Ltd.     

Syntheses and Structures of Acetyl‐Acetonato‐Alumo‐Diphenylsilanolates with Magnesium(II), Iron(II), Iron(III), Cobalt(II), and Nickel(II)

Bis(acetylacetonate)alumo‐oxo‐tetraphenyldisiloxane‐metal(II) dihydrates [(acac)₂Al(O–SiPh₂–O–SiPh₂–O)]₂M(H₂O)₂ (M = Mg, Fe, Co, Ni) were obtained from the corresponding acetyl‐acetonate‐dihydrates (acac)₂M(H₂O)₂ by reaction with the alumosiloxane [O–Ph₂Si–O–SiPh₂–O]₄Al₄(OH)₄. These new compounds display two acac ligands at the aluminum atoms as well as disilatrioxy chains linking the two aluminum atoms forming a (Al–O–Si–O–Si–O)₂ cycle (X‐ray structure analyses). Within this cycle the divalent metal ions M²⁺, to which two water molecules in trans positions are linked, are installed in almost planar MO₄ coordination spheres. Using water free (acac)₂Ni a different product forms: both reactants combine in a 2:1 ratio to yield [O–Ph₂Si–O–SiPh₂–O]₄Al₄(OH)₂O(OH₂)Ni₂(acac)₄. Here, three of the acac ligands were transposed to the aluminum atoms. The nickel atoms are in a distorted octahedral coordination mode from oxygen atoms of the ligands. When iron(III)tris(acetylacetonate) reacts with the alumosiloxane [O–Ph₂Si–O–SiPh₂–O]₃Al₂O(OH)Fe₂(acac)₃ was isolated, in which the two iron atoms still display one of the acac ligands. One of the aluminum atoms is in a tetrahedral oxygen environment, whereas the other is in the center of a trigonal bi‐pyramid formed of oxygen atoms either of the siloxane or of acac. The iron atoms have five‐ or sixfold coordination from oxygen atoms of siloxane, acac, hydroxide or oxide.     

Synthesis and Investigation of 1,3‐Bis(5‐nitraminotetrazol‐1‐yl)propan‐2‐ol and its Salts

1,3‐Bis(5‐nitraminotetrazol‐1‐yl)propan‐2‐ol ( 5 ) was prepared by the reaction of 5‐aminotetrazole and 1,3‐dichloroisopropanol under basic conditions. Obtained 1,3‐bis(5‐aminotetrazol‐1‐yl)propan‐2‐ol ( 3 ) was nitrated with 100 % nitric acid. In this context in situ hydrolysis of the nitrate ester was studied. Metal and nitrogen‐rich salts of the neutral compound 5 were prepared and analyzed. Crystal structures of three salts and the sensitivities toward impact, friction and electrostatic discharge were determined as well. The performance values of the compounds were calculated using the EXPLO5 program. A detailed comparison of the different salts is also enclosed.     

Synthesis,Structure, and Photoluminescence Properties of an Organically‐Templated Uranyl Selenite

The organically‐templated uranyl selenite, (H₂en)[(UO₂)(SeO₃)(HSeO₃)](NO₃) · 0.5H₂O ( 1 ) (en = 1,2‐ethylenediamine) was synthesized and characterized by elemental analyses, IR spectroscopy, TG, and single‐crystal X‐ray diffraction. Compound 1 crystallizes in the orthorhombic system, space group Pbca, with a = 13.170(3) Å, b = 11.055(2) Å, c = 18.009(4) Å, V = 2621.8(9) ų, M = 1316.19, Z = 4, D_cal = 3.334 g · cm^–3, μ(Mo‐K_α) = 17.998 mm^–1, GOF = 1.059, R₁ = 0.0263, wR₂ = 0.0532 [I>2σ(I)]. The X‐ray diffraction analysis reveals that compound 1 has a three‐dimensional (3D) supramolecular structure. It contains negatively charged [UO₂(HSeO₃)(SeO₃)]^– inorganic anion layers and is balanced by [H₂en]²⁺ cations and NO₃^– anions located in the interlayers. Furthermore, the photoluminescence properties of 1 were investigated.     

New Structure Type among Octahydrated Rare‐Earth Sulfates, β‐Ce2(SO4)3·8H2O,and a new Ce2(SO4)3·4H2O Polymorph

Syntheses, crystal structures and thermal behavior of two new hydrated cerium(III) sulfates are reported, Ce₂(SO₄)₃·4H₂O ( I ) and β‐Ce₂(SO₄)₃·8H₂O ( II ), both forming three‐dimensional networks. Compound I crystallizes in the space group P2₁/n. There are two non‐equivalent cerium atoms in the structure of I , one nine‐ and one ten‐fold coordinated to oxygen atoms. The cerium polyhedra are edge sharing, forming helically propagating chains, held together by sulfate groups. The structure is compact, all the sulfate groups are edge‐sharing with cerium polyhedra and one third of the oxygen atoms, belonging to sulfate groups, are in the S–Oμ₃–Ce₂ bonding mode. Compound II constitutes a new structure type among the octahydrated rare‐earth sulfates which belongs to the space group Pn. Each cerium atom is in contact with nine oxygen atoms, these belong to four water molecules, three corner sharing and one edge sharing sulfate groups. The crystal structure is built up by layers of [Ce(H₂O)₄(SO₄)]_nⁿ⁺ held together by doubly edge sharing sulfate groups. The dehydration of II is a three step process, forming Ce₂(SO₄)₃·5H₂O, Ce₂(SO₄)₃·4H₂O and Ce₂(SO₄)₃, respectively. During the oxidative decomposition of the anhydrous form, Ce₂(SO₄)₃, into the final product CeO₂, small amount of CeO(SO₄) as an intermediate species was detected.     

Nitrogen‐Rich Alkali Metal Salts (Na and K) of [Bis(N,N‐bis(1H‐tetrazol‐5‐yl)amine)‐zinc(II)] Anion: Syntheses,Crystal Structures,and Energetic Properties

Two nitrogen‐rich alkali metal salts based on nitrogen‐rich anion [Zn(bta)₂]^2–: {[Na₂Zn(bta)₂(H₂O)₈] · H₂O}_n ( 1 ) and {[K₂Zn(bta)₂(H₂O)₄]}_n ( 2 ) were synthesized by reactions of alkali hydroxide, N,N‐bis(1H‐tetrazol‐5‐yl)amine (H₂bta), and zinc chloride in aqueous solutions. The crystal structures of 1 and 2 were determined by low temperature single‐crystal X‐ray diffraction and fully characterized by elemental analysis and FT‐IR spectroscopy. The structures demonstrate that an infinite 1‐dimensional (1D) chain structure is constructed by Na⁺ ions and bridging water molecules in compound 1 , which is connected by extensive hydrogen bonds forming a complex 3D network, whereas compound 2 features a more complicated 3D metal‐organic framework (MOF). The thermal behaviors of 1 and 2 were investigated by differential scanning calorimetry (DSC) measurements. The DSC results illustrate that both compounds exhibit high thermal stabilities (decomposition temperature > 345 °C). In addition, the heats of formation were calculated on the basis of the experimental constant‐volume energies of combustion measured by using bomb calorimetry. Lastly, the sensitivities towards impact and friction were assessed according to Bundesamt für Materialforschung (BAM) standard methods.     

Hydrogen‐Bonded Complexes between 4‐Alkoxystilbazoles and Fluorophenols: Solid‐State Structures and Liquid Crystallinity

48 new hydrogen‐bonded complexes have been prepared by combining 16 fluorophenols of general formula C₆F_nH_5?nOH with three different alkoxystilbazoles (butyloxy‐, octyloxy‐ and dodecyloxy‐). Single‐crystal X‐ray structures were obtained for 10 of the 16 complexes of octyloxystilbazole from which it was found that most of the structures could be collected into one of two groups according to both the motif shown by the complex and by the solid‐state packing. Because all but one crystallised in the P$\bar 1$ space group, meaningful comparisons could be drawn and it was observed that six structures were extremely close in nature so that significant molecular overlap was found. On this basis, doubt is cast on the significance of some of the weaker intermolecular contacts found in the solid state. 40 of the new complexes showed liquid‐crystal properties and it was found that although complexes of butyloxystilbazole were all nematic, almost all of those with dodecyloxystilbazole showed a smectic A (SmA) phase. Complexes of octyloxystilbazole showed a mixture of both. Structure/property correlations showed that clearing points were independent of the pK_a of the phenol. The most stable mesophases were found when the fluorophenol contained a fluorine at the 2‐position, which was interpreted in terms of the formation of an intramolecular H???F hydrogen bond to give a six‐membered ring linking the two components into a stable, coplanar conformation. The least stable mesophases were found when no such ring formation was possible and the phenol was relatively free to move.     

Synthesis,Crystal Structure and Selected Properties of Mono(dithiocarbamato)‐gold(I), AuS2CNH2

The title compound AuS₂CNH₂ was prepared from an aqueous solution by reaction of dicyanidoaurate [Au(CN)₂]^– with excess of ammoniumdithiocarbamate NH₄S₂CN H ₂ at pH ≈ 2. The compound crystallizes in the orthorhombic space group Cmma with a = 6.4597(2), b = 12.6556(3), and c = 5.3235(1) Å. The crystal structure comprises linear S–Au–S dumbbells forming unbranched zigzag chains in combination with the dithiocarbamate ligands. The three‐dimensional arrangement of the molecules is realized by aurophilic Au^I–Au^I and hydrogen bonding interactions, respectively. AuS₂CNH₂ presents orange luminescence due to a broad emission band between 12000 cm^–1 and 23000 cm^–1 (ν = 26316 cm^–1).     

Crystallographic report: Crystal and molecular structure of tetramethylammoniumdiisothiocyanatotriphenyltin(IV), [NMe4SnPh3(NCS)2]

The structure of NMe₄SnPh₃(NCS)₂ is molecular, without any significant intermolecular contacts in the lattice. The trigonal plane around the tin atom is defined by three carbon atoms from the phenyl groups and the axial positions occupied by the NCS groups. Copyright © 2003 John Wiley & Sons, Ltd.     

Structural Observations of Heterometallic Uranyl Copper(II) Carboxylates and Their Solid‐State Topotactic Transformation upon Dehydration

The hydrothermal reactions of uranyl nitrate and metallic copper with aromatic polycarboxylic acids gave rise to the formation of five heterometallic UO₂²⁺? Cu²⁺ coordination polymers: (UO₂)Cu(H₂O)₂(1,2‐bdc)₂ ( 1 ; 1,2‐bdc=phthalate), (UO₂)Cu(H₂O)₂(btec) ? 4 H₂O ( 2 ) and (UO₂)Cu(btec) ( 2′ ; btec=pyromellitate), (UO₂)₂Cu(H₂O)₄(mel) ( 3 ; mel=mellitate), and (UO₂)₂O(OH)₂Cu(H₂O)₂(1,3‐bdc) ? H₂O ( 4 ; 1,3‐bdc=isophthlalate). Single‐crystal X‐ray diffraction (XRD) analysis of compound 1 revealed 2D layers of chains of UO₈ and CuO₄(H₂O)₂ units that were connected through the phthalate ligands. In compound 2 , these sheets were connected to each other through the two additional carboxylate arms of the pyromellitate, thus resulting in a 3D open‐framework with 1D channels that trapped water molecules. Upon heating, free and bonded water species (from Cu? OH₂) were evacuated from the structure. This thermal transition was followed by in situ XRD and IR spectroscopy. Heating induced a solid‐state topotactic transformation with the formation of a new set of Cu? O interactions in the crystalline anhydrous structure ( 2′ ), in order to keep the square‐planar environment around the copper centers. The structure of compound 3 was built up from trinuclear motifs, in which one copper center, CuO₄(OH₂)₂, was linked to two uranium units, UO₅(H₂O)₂. The assembly of this trimer, “U₂Cu”, with the mellitate generated a 3D network. Complex 4 contained a tetranuclear uranyl core of UO₅(OH)₂ and UO₆(OH) units that were linked to two copper centers, CuO(OH)₂(H₂O)₂, which were then connected to each other through isophthalate ligands and U?O? Cu interactions to create a 3D structure. The common structural feature of these different compounds is a bridging oxo group of U?O? Cu type, which is reflected by apical Cu? O distances in the range 2.350(3)–2.745(5) Å. In the case of a shorter Cu? O distance, a slight lengthening of the uranyl bond (U?O) is observed (e.g., 1.805(3) Å in complex 4 ).     

Manganese(IV) Corroles with σ‐Aryl Ligands

Different pathways for the preparation of organometallic manganese(IV) corroles with σ‐aryl ligands have been evaluated. The treatment of a manganese(III) corrole with Grignard reagents PhMgX (X = Cl, Br), followed by aerial oxidation yields oxidized halogenido complexes [(cor)Mn^IVX] instead of the anticipated organometallic compounds. Reaction of these halogenido species, especially the bromido compound, with excess Grignard reagents or with lithium aryls results in the formation of the desired σ‐aryl compounds via salt metatheses. Three examples of this class of rare complexes have been characterized by means of optical and ¹H NMR spectroscopy, and in two cases single crystal X‐ray diffraction studies have been carried out. In the crystal, the molecular structures of the σ‐phenyl‐ and the σ‐(p‐bromophenyl) derivatives were observed to be very similar, albeit both species pack in different pattern.     

Synthesis and Solid‐State Structures of a Tetrathiafulvalene‐Conjugated Bistetracene

A tetrathiafulvalene (TTF)‐conjugated bistetracene was synthesized and characterized in the molecular electronic structures based on the spectroscopic measurements and the single‐crystal X‐ray diffraction analysis. UV/Vis absorption and electrochemical measurements of 5 revealed the considerable electronic communication between two tetracenedithiole units by through‐bond and/or through‐space interactions. The difference in the crystal‐packing structures of 5 , showing polymorphism, results in a variety of intermolecular electronic‐coupling pattern. Of these, the π‐stacking structure of 5 A gave a large transfer integral of HOMOs (97 meV), which value is beyond hexacene and rubrene, thus, quite beneficial to achieve the high hole mobility.     

A New Chair‐shaped Conformation Containing HgHgOHgHgO: Synthesis and Structure of Hg4(L2)2(NO3)4 (L2 = morpholin‐4‐ylpyridin‐2‐ylmethyleneamine)

. The complex Hg₄(L²)₂(NO₃)₄ ( 1 ) (L² = morpholin‐4‐ylpyridin‐2‐ylmethyleneamine) has been synthesized and characterized by CHN analysis, IR, and UV/Vis spectroscopy. The crystal structure of 1 was determined using single‐crystal X‐ray diffraction. The crystal structure of 1 contains four mercury atoms, four nitrate anions (two terminal and two bridge ones) and two L² ligand molecules. A chair shape, six‐membered ring is formed with the sequence OHgHgOHgHg built from Hg–Hg dumbbells and oxygen atoms from the nitrate co‐ligands. In the crystal structure, the asymmetric unit of the compound is built up by one‐half of the molecule. It contains the Hg₂²⁺ moiety with a mercury–mercury bonded core, in which one diimine ligand is coordinated to one of the mercury atoms. The nitrate anions act as anisobidentate and bidentate ligands.     

Solid‐State Form Screen of Cardiosulfa and Its Analogues

Cardiosulfa is a biologically active sulfonamide molecule that was recently shown to induce abnormal heart development in zebrafish embryos through activation of the aryl hydrocarbon receptor (AhR). The present report is a systematic study of solid‐state forms of cardiosulfa and its biologically active analogues that belong to the N‐(9‐ethyl‐9H‐carbazol‐3‐yl)benzene sulfonamide skeleton. Cardiosulfa (molecule 1 ; R¹=NO₂, R²=H, R³=CF₃), molecule 2 (H, H, CF₃), molecule 3 (CF₃, H, H), molecule 4 (NO₂, H, H), molecule 5 (H, CF₃, H), and molecule 6 (H, H, H) were synthesized and subjected to a polymorph search and solid‐state form characterization by X‐ray diffraction, differential scanning calorimetry (DSC), variable‐temperature powder X‐ray diffraction (VT‐PXRD), FTIR, and solid‐state (ss) NMR spectroscopy. Molecule 1 was obtained in a single‐crystalline modification that is sustained by N? H???π and C? H???O interactions but devoid of strong intermolecular N? H???O hydrogen bonds. Molecule 2 displayed a N? H???O catemer C(4) chain in form I, whereas a second polymorph was characterized by PXRD. The dimorphs of molecule 3 contain N? H???π and C? H???O interactions but no N? H???O bonds. Molecule 4 is trimorphic with N? H???O catemer in form I, and N? H???π and C? H???O interactions in form II, and a third polymorph was characterized by PXRD. Both polymorphs of molecule 5 contain the N? H???O catemer C(4) chain, whereas the sulfonamide N? H???O dimer synthon R₂²(8) was observed in polymorphs of 6 . Differences in the strong and weak hydrogen‐bond motifs were correlated with the substituent groups, and the solubility and dissolution rates were correlated with the conformation in the crystal structure of 1 , 2 , 3 , 4 , 5 , 6 . Higher solubility compounds, such as 2 (10.5 mg mL^?1) and 5 (4.4 mg mL^?1), adopt a twisted confirmation, whereas less‐soluble 1 (0.9 mg mL^?1) is nearly planar. This study provides practical guides for functional‐group modification of drug lead compounds for solubility optimization.     

Self‐Assembly and Structure of Cobalt(II) Complexes Using Diaminodiamide Ligands

The self‐assembly of Co(II) with two diaminodiamide ligands, 4,7‐diazadecanediamide and 4,8‐diazaundecanediamide, gave two different crystals, [(C₈H₁₈N₄O₂)Co(OH)₂Co(C₈H₁₈N₄O₂)]Cl₂ ( 1 ) [Co(C₉H₂₀N₄O₂)(Cl)(H₂O)]·Cl·2H₂O ( 2 ). Structures of 1 and 2 were characterized by single‐crystal X‐ray diffraction analysis. Structural data for 1 shows a novel type of binuclear complex with distorted octahederal coordination geometry around the Co atoms through the hydroxo bridges. By using inter‐connector N‐H···N hydrogen bonding interactions as building forces, each cationic moiety [(C₈H₁₈N₄O₂)Co(OH)₂Co(C₈H₁₈N₄O₂)]²⁺ is linked to neighboring ones, producing a charged hydrogen‐bonded 1D chain‐like structure. The chains are further connected into a 2D layer in a (4,4)‐topology via N‐H···Cl_free hydrogen‐bonding interactions. Structural data for 2 indicate that the cobalt atom adopts a six‐coordinated N₂O₄ environment, giving a distorted octahedral geometry, where two N‐ and two O‐donor sets of ligand located at equatorial positions and one water and one chloride occupied at axial positions. Through NH···Cl‐Co and OH···Cl‐Co contacts, each cationic moiety [Co(C₉H₂₀N₄O₂)(Cl)(H₂O)]⁺ in 2 is linked to neighboring ones, producing a charged hydrogen‐bonded 1D chainlike structure. Thus, the crystal‐engineering approach has proved successful in the solid‐state packing due to steric strain effect of the diaminodiamide ligand.     

4‐Nitro‐3‐(5‐tetrazole)furoxan and Its Salts: Synthesis,Characterization, and Energetic Properties

A series of new energetic salts based on 4‐nitro‐3‐(5‐tetrazole)furoxan (HTNF) has been synthesized. All of the salts have been fully characterized by nuclear magnetic resonance (¹H and ¹³C), infrared (IR) spectroscopy, elemental analysis, and differential scanning calorimetry (DSC). The crystal structures of neutral HTNF ( 3 ) and its ammonium ( 4 ) and N‐carbamoylguanidinium salts ( 9 ) have been determined by single‐crystal X‐ray diffraction analysis. The densities of 3 and its nine salts were found to range from 1.63 to 1.84 g cm^?3. Impact sensitivities have been determined by hammer tests, and the results ranged from 2 J (very sensitive) to >40 J (insensitive). Theoretical performance calculations (Gaussian 03 and EXPLO 5.05) provided detonation pressures and velocities for the ionic compounds 4 – 12 in the ranges 25.5–36.2 GPa and 7934–8919 m s^?1, respectively, which make them competitive energetic materials.     

One‐Dimensional Channels Encapsulated in Supramolecular Networks Constructed of Zinc(II), Manganese(II), or ­Nickel(II) Atoms with 3‐(Carboxymethyl)‐2, 7‐dimethyl‐3H‐benzo[d]imidazole‐5‐carboxylic Acid

Four complexes with supramolecular architectures, namely, MZCA · 3H₂O ( 1 ), [Zn(H₂O)₆]²⁺ · [MZCA]₂ · [H₂O]₆ ( 2 ), [Mn(MZCA)₂(H₂O)₄] · 2H₂O ( 3 ), and [Ni(MZCA)₂(H₂O)₄] · 2H₂O ( 4 ) [MZCA = 3‐(carboxymethyl)‐2, 7‐dimethyl‐3H‐benzo[d]imidazole‐5‐carboxylic acid], were synthesized and characterized by elemental analysis, IR spectroscopy, and single‐crystal X‐ray diffraction. Complexes 1 and 2 display a remarkable 3D network with 1D hydrophilic channels. Complexes 3 and 4 are isostructural and exhibit a 3D structure encapsulating 1D 24‐membered ring microporous channels. The UV/Vis and fluorescent spectra were measured to characterize complexes 1 – 4 . The thermal stability of complexes 2 – 4 were also examined.     

Structural Investigation of Homoleptic Lanthanide(III) Tris(pivalamidinates), [tBuC(NiPr)2]3Ln (Ln = Ce,Eu, Tb)

Three new homoleptic lanthanide(III) tris(pivalamidinates), [tBuC(NiPr)₂]₃Ln (Ln = Ce ( 1 ), Eu ( 2 ), Tb ( 3 )) were synthesized by reaction of anhydrous LnCl₃ with 3 equivalents of in situ prepared Li[tBuC(NiPr)₂] in THF. X‐ray structural analyses confirmed the presence of homoleptic, unsolvated tris(amidinates) in which the central Ln³⁺ ions are coordinated by three chelating pivalamidinate anions in a distorted all‐nitrogen trigonal prismatic arrangement. Compounds 1 – 3 all crystallize in the monoclinic system, with 1 and 3 containing solvent of crystallization ( 1 : toluene, 3 : n‐pentane) whereas the europium derivative 2 is unsolvated.