Assessment and comparison of three high-aluminum fly ash utilization scenarios in Inner Mongolia, China using an eco-efficiency indicator.

Utilization of fly ash is of great importance in China in the context of resource and environmental crises. Different fly ash utilization processes are proposed, and some have been practically applied. However, none of these fly ash utilization pathways has been evaluated comprehensively by integrating both environmental and economic perspectives. In this study, three high-aluminum fly ash utilization methods in Mongolia were assessed and compared based on the concept of eco-efficiency. The environmental assessment was conducted in accordance with life-cycle assessment principles, and a monetization-weighting approach was applied to obtain social willingness-to-pay as a reflection of environmental impact. The environmental assessment results revealed that the reuse of fly ash had significant advantage for saving primary resource, while solid waste, depletion of water, and global warming were the three highest environmental impacts from the life cycle perspective. The economic performance assessment showed positive net profits for fly ash utilization, but high value-added products were not necessarily indicative of better economic performance due to the relatively high operation cost. Comparison of the eco-efficiency indicators (EEIs) implied that the process of scenario 1#, which produced mullite ceramic and active calcium silicate, was the most recommended out of the three scenarios on the present scale. This judgment was consistent with the evaluation of the resource utilization rate. The present study showed that the EEI could be used to compare different fly ash utilization processes in a comprehensive and objective manner, thus providing definitive and insightful suggestions for decision-making and technical improvement.

Synthesis, structures, and magnetism of three 1D Mn(III) chains with oxazoline-based ligands.

Three novel Mn(III) polymers, [Mn(phox)(2)(N(3))](n) (1), [Mn(Etphox)(2)(N(3))](n) (2), and [Mn(Etphox)(2)(C(2)N(3))](n) (3), using achiral ligand Hphox (Hphox = 2-(4,5-dihydrooxazol-2-yl)phenol) and chiral ligand HEtphox (HEtphox = 2-(4-ethyl-4,5-dihydrooxazol-2-yl)phenol) were synthesized and structurally and magnetically characterized. All complexes are of 1D chain structures and form 2D frameworks by weak interactions. The adjacent 1D chains of complex 1 are connected by face-to-face pi-pi interactions, C-H...pi interactions, and hydrogen bonding, which leads to the formation of a supramolecular 2D sheet structure. The three compounds show antiferromagnetic coupling between Mn(III) ions. And compound 2 is a spin-canted weak ferromagnet with T(N) = 5.6 K, showing metamagnetic behavior with a two-step magnetic phase transition.

One-dimensional ferromagnetically coupled bimetallic chains constructed with trans-[Ru(acac)2(CN)2]-: syntheses, structures, magnetic properties, and density functional theoretical study.

Four cyano-bridged 1D bimetallic polymers have been prepared by using the paramagnetic building block trans-[Ru(acac)(2)(CN)(2)](-) (Hacac=acetylacetone): {[{Ni(tren)}{Ru(acac)(2)(CN)(2)}][ClO(4)].CH(3)OH}(n) (1) (tren=tris(2-aminoethyl)amine), {[{Ni(cyclen)}{Ru(acac)(2)(CN)(2)}][ClO(4)].CH(3)OH}(n) (2) (cyclen=1,4,7,10-tetraazacyclododecane), {[{Fe(salen)}{Ru(acac)(2)(CN)(2)}]}(n) (3) (salen(2-)=N,N'-bis(salicylidene)-o-ethyldiamine dianion) and [{Mn(5,5'-Me(2)salen)}(2){Ru(acac)(2)(CN)(2)}][Ru(acac)(2)(CN)(2)].2CH(3)OH (4) (5,5'-Me(2)salen=N,N'-bis(5,5'-dimethylsalicylidene)-o-ethylenediimine). Compounds 1 and 2 are 1D, zigzagged NiRu chains that exhibit ferromagnetic coupling between Ni(II) and Ru(III) ions through cyano bridges with J=+1.92 cm(-1), zJ'=-1.37 cm(-1), g=2.20 for 1 and J=+0.85 cm(-1), zJ'=-0.16 cm(-1), g=2.24 for 2. Compound 3 has a 1D linear chain structure that exhibits intrachain ferromagnetic coupling (J=+0.62 cm(-1), zJ'=-0.09 cm(-1), g=2.08), but antiferromagnetic coupling occurs between FeRu chains, leading to metamagnetic behavior with T(N)=2.6 K. In compound 4, two Mn(III) ions are coordinated to trans-[Ru(acac)(2)(CN)(2)](-) to form trinuclear Mn(2)Ru units, which are linked together by pi-pi stacking and weak Mn...O* interactions to form a 1D chain. Compound 4 shows slow magnetic relaxation below 3.0 K with phi=0.25, characteristic of superparamagnetic behavior. The Mn(III)...Ru(III) coupling constant (through cyano bridges) and the Mn(III)...Mn(III) coupling constant (between the trimers) are +0.87 and +0.24 cm(-1), respectively. Compound 4 is a novel single-chain magnet built from Mn(2)Ru trimers through noncovalent interactions. Density functional theory (DFT) combined with the broken symmetry state method was used to calculate the molecular magnetic orbitals and the magnetic exchange interactions between Ru(III) and M (M=Ni(II), Fe(III), and Mn(III)) ions. To explain the somewhat unexpected ferromagnetic coupling between low-spin Ru(III) and high-spin Fe(III) and Mn(III) ions in compounds 3 and 4, respectively, it is proposed that apart from the relative symmetries, the relative energies of the magnetic orbitals may also be important in determining the overall magnetic coupling in these bimetallic assemblies.

trans-[Os(III)(salen)(CN)(2)](-): a new paramagnetic building block for the construction of molecule-based magnetic materials.

A novel dicyanoosmium(III) complex, trans-Ph(4)P[Os(III)(salen)(CN)(2)].CH(2)Cl(2).H(2)O (1; Ph(4)P(+) = tetraphenylphosphonium cation, salen(2-) = N,N'-ethylenebis(salicylideneaminato) dianion), has been synthesized and structurally characterized. Reactions of 1 with [Cu(Me(3)tacn)(H(2)O)(2)](ClO(4))(2) (Me(3)tacn = 1,4,7-trimethyl-1,4,7-triazacyclononane) under different conditions produce the 1-D ferromagnetic zigzag chains [Os(salen)(CN)(2)](2)[Cu(Me(3)tacn)].CH(3)OH (2) and [Os(salen)(CN)(2)][Cu(Me(3)tacn)].ClO(4) (3).

Thiacalix[4]arene-supported planar Ln(4) (Ln = Tb(III), Dy(III)) clusters: toward luminescent and magnetic bifunctional materials.

This paper reports the syntheses, crystal structures, and luminescent and magnetic properties of four tetranuclear Tb(III) (1 and 3) and Dy(III) (2 and 4) complexes supported by p-phenylthiacalix[4]arene (H(4)PTC4A) and p-tert-butylthiacalix[4]arene (H(4)TC4A). All four frameworks can be formulated as [Ln(III)(4)(PTC4A/TC4A)(2)(mu(4)-OH)Cl(3)(CH(3)OH)(2)(H(2)O)(3)], and some methanol and water solvent molecules are occupied in the interstices. The compounds are featured with a sandwichlike unit constructed by two tail-to-tail calixarene molecules and a planar tetragonal (mu(4)-OH)Ln(4) cluster. The photoluminescent analyses suggest that there is an efficient ligand-to-Ln(III) energy transfer for compounds 1-3 and H(4)PTC4A is a more efficient "antenna" than H(4)TC4A. The Dy(III) compounds exhibit slow magnetic relaxation behavior of single-molecule magnet nature. The substitution of the t-Bu group with a phenyl group at the up-rim of thiacalix[4]arene leads to different extended structures and physical properties of as-synthesized compounds.

A {Co32} nanosphere supported by p-tert-butylthiacalix[4]arene.

Calixarene-capped Co(32) clusters are constructed by a sodalite Co(II)(24) cage and an encapsulated Co(III)(8) cube. The spherical units are arranged into three isomeric structures, two of which are stacked by the bcc lattices and the third of which is assembled by the cubic closest packing of the spherical units.

Two EE-azido-bridged nickel(II) layered compounds: vigorous twisted torsion angle Ni-N3-Ni results in ferromagnetic behavior.

Two coordination polymers, Ni(endi)(N(3))(2) (endi = 1,2-bis(tetrazol-1-yl)ethane) (1) and Ni(4-acpy)(2)(N(3))(2) (4-acpy = 4-acetylpyridine) (2), are obtained by employing a couple of cobalt complex as references. Both compounds have similar 2D (4,4) EE azide-nickel layer structures, but different interlayer separations. Their EE azide bridges are vigorously twisted, with the torsion angle tau value 88.3 degrees and 107.6 degrees for 1 and 89.2 degrees for 2. Different from most EE azide compounds, ferromagnetism is distinctly present, ordering below T(c) = 25 K for 1 and T(c) = 23 K for 2. Fitting of magnetic susceptibility data using the spin Hamiltonian H = -2J SigmaS(1)S(2) gives the ferromagnetic intralayer coupling J = 14.70(6) cm(-1) for 1 and 14.32(0) cm(-1) for 2, respectively. The magnetostructural correlations of 1 have been calculated using the density function theory based method. The computational results are consistent with the trend of the experimental data. One possible mechanism was proposed to explain the emergence of ferromagnetism based on the theoretical studies, and the ferromagnet construction approach was also proposed accordingly.

Two Mn(II)(2)Ln(III)(4) (Ln = Gd, Eu) hexanuclear compounds of p-tert-butylsulfinylcalix[4]arene.

Two 3d-4f heterometallic compounds of p-tert-butylsulfinylcalix[4]arene were synthesized by the solvothermal method and characterized by some hinged double-dumbbell-like subunits in which two perpendicular dumbbell entities were constructed by an in-between isosceles triangle Mn(II)Ln(III)(2), and two tail-to-tail calixarene molecules, and hinged by the lanthanide-sulfinyl group bonding. The magnetic properties of the title compounds were examined.

Diversity of azido magnetic chains constructed with flexible ligand 2,2'-dipyridylamine.

By employing a flexible molecule, 2,2'-dipyridylamine (dpa), as a bidentate coligand, three azide-bridged one-dimensional coordination polymers, [M(dpa)(N(3))(2)](n) (M = Cu, 1.Cu; Co, 2.Co) and [Ni(dpa)(OAc)(0.5)(N(3))(1.5)(H(2)O)](n) (3.Ni), have been successfully synthesized and structurally and magnetically characterized. They show versatile one-dimensional chain structures. 1.Cu is an EO-N(3) bridged uniform chain; 2.Co is an alternative chain linked by two EO-N(3) and two EE-N(3) bridges. Interestingly, 3.Ni is a zigzag chain linked alternatively by one EE-N(3) and a novel 3-fold bridge, which is composed of two EO-N(3) and one acetate group. This series of azido complexes demonstrates that the flexibility of the dpa ligand plays an important role in directing the structures of the final products. Magnetic studies reveal dominant intrachain antiferromagnetic couplings in compound 1.Cu. Compounds 2.Co and 3.Ni are weak ferromagnets due to the spin canting, with critical temperatures of 12.4 and 32.5 K, respectively.

Syntheses, structures and properties of seven isomorphous 1D Ln3+complexes Ln(BTA)(HCOO)(H2O)3 (H2BTA = bis(tetrazoly)amine, Ln = Pr, Gd, Eu, Tb, Dy, Er, Yb) and two 3D Ln3+ complexes Ln(HCOO)3 (Ln = Pr, Nd).

Seven isomorphous 1D chain Ln3+ complexes Ln(BTA)(HCOO)(H2O)3 (Ln = Pr (1), Gd (2), Eu (3), Tb (4) Dy (5), Er (6) and Yb (7)), and two formate coordinating and bridging 3D Ln3+ complexes Ln(HCOO)3 (Ln = Pr (8) and Nd (9)) have been synthesized and characterized by single crystal X-ray diffraction analysis. Although the Ln3+ ions in 1-7 have different radius, the trivalent lanthanide ions in 1-7 show the same coordinated environment. The well-defined single crystal structures of 8 and 9 are first samples for formate-bridged Ln3+ metallic complexes. The luminescent properties of solid samples of 2-5 at room temperature and the magnetic property of 2 have been also reported and discussed in this paper.

Cobalt-lanthanide coordination polymers constructed with metalloligands: a ferromagnetic coupled quasi-1D Dy3+ chain showing slow relaxation.

Four types of cobalt-lanthanide heterometallic compounds based on metalloligand Co(2,5-pydc)(3) (3-) (2,5-H(2)pydc=pyridine-2,5-dicarboxylate acid), [Ln(2)Co(2)(2,5-pydc)(6)(H(2)O)(4)](n) 2n H(2)O (1) (Ln=Tb, Dy for 1 a, 1 b respectively), [Tb(2)Co(2)(2,5-pydc)(6)(H(2)O)(4)](n)3n H(2)O (2), [Tb(2)Co(2)(2,5-pydc)(6)(H(2)O)(9)](n)4n H(2)O (3), and [LaCo(2,5-pydc)(3)(H(2)O)(2)](n)2n H(2)O (4) have been synthesized. Compound 1 has a layer structure with well-isolated carboxylate-bridged Ln(3+) chains, compound 2 is a three-dimensional (3D) porous network with Tb(3+) chains that are also well isolated and carboxylate bridged, 3 is a layer structure based on dinuclear units, and 4 is a 3D network with boron nitride (BN) topology. DC magnetic studies reveal ferromagnetic coupling in all the carboxylate-bridged Ln(3+) chains in 1 a, 1 b, and 2. Compared to the silence of the out-of-phase ac susceptibility of 2, above 1.9 K the magnetic relaxation behavior of both 1 a and 1 b is slow like that of a single-chain magnet.

Honeycomb layer of cobalt(II) azide hydrazine showing weak ferromagnetism.

Using hydrazine (N2H4) as a cobridge with azide, a honeycomb-layered cobalt(II) coordination polymer, Co(N2H4)(N3)2 (1), is obtained that exhibits spin-canted weak ferromagnetism with TN of 13.5 K.