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201.
Treatment of two kinds of ferrocenyl-substituted carboxylate ligands (3-ferrocenyl-2-crotonic acid, HOOC-CH=(CH(3))CFc (Fc=(eta(5)-C(5)H(5))Fe(eta(5)-C(5)H(4))) or O-ferrocecarbonyl benzoic acid, o-HOOCC(6)H(4)COFc with Pb(OAc)(2).3H(2)O, Zn(OAc)(2).2H(2)O, or Cd(OAc)(2).2H(2)O) resulted in four novel ferrocene-containing coordination polymers [[Pb(mu(2)-eta(2)-OOCCH=(CH(3))CFc)(2)].MeOH](n) (1), [[Zn(o-OOCC(6)H(4)COFc)(2)(4,4'-bipy)(H(2)O)(2)].2MeOH.2H(2)O](n) (4,4'-bipy = 4,4'-bipyridine) (2), [[Cd(o-OOCC(6)H(4)COFc)(2)(bpe)(MeOH)(2)].2H(2)O](n) (bpe = 1,2-bis(4-pyridyl)ethene) (3), and [Pb(o-OOCC(6)H(4)COFc)(eta(2)-o-OOCC(6)H(4)COFc)(bpe)](n)() (4). Their crystal structures have been characterized by single X-ray determinations. In polymer 1, Pb(II) ions are bridged by tridentate FcC(CH(3))=CHCOO(-) anions, forming an infinite chain [Pb(mu(2)-eta(2)-OOC=CH(CH(3))CFc)(2)](n). In polymers 2-4, there are three kinds of components, metal ions, o-FcCOC(6)H(4)COO(-) units, and organic bridging ligands. The bipyridine-based ligands connect metal ions leading to a one-dimensional chain with o-FcCOC(6)H(4)COO(-) units acting as monodentate or chelate ligands in the side chain. Such coordination polymers containing ferrocenyl-substituted carboxylate and bipyridine-based ligands are very rare. The solution-state differential pulse voltammetries of polymers 1-4 were determined. The results indicate that the half-wave potential of the ferrocenyl moieties is influenced by the Pb(II) ions in polymer 1 and strongly influenced by Zn(II), Cd(II), or Pb(II) ions in polymers 2-4. The thermal properties of the four polymers were also investigated. 相似文献
202.
The novel ternary solid complex Gd(C5H8NS2)3(C12H8N2) has been obtained from the reaction of hydrous gadolinium chloride, ammonium pyrrolidinedithiocarbamate (APDC), and 1,10-phenanthroline
(o-phen · H2O) in absolute ethanol. The complex was described by an elemental analysis, TG-DTG, and an IR spectrum. The enthalpy change
of the complex formation reaction from a solution of the reagents, Δr
H
m
ϑ
(sol), and the molar heat capacity of the complex, c
m
, were determined as being − 15.174 ± 0.053 kJ/mol and 72.377 ± 0.636 J/(mol K) at 298.15 K by using an RD496-III heat conduction
microcalorimeter. The enthalpy change of a complex formation from the reaction of the reagents in a solid phase, Δr
H
m
ϑ
(s), was calculated as being 52.703 ± 0.304 kJ/mol on the basis of an appropriate thermochemical cycle and other auxiliary
thermodynamic data. The thermodynamics of the formation reaction of the complex was investigated by the reaction in solution.
Fundamental parameters, the activation enthalpy (ΔH
≠
ϑ
), the activation entropy (ΔS
≠
ϑ
), the activation free energy (ΔG
≠
ϑ
), the apparent reaction rate constant (k), the apparent activation energy (E), the preexponential constant (A), and the reaction order (n), were obtained by the combination of the thermochemical data of the reaction and kinetic equations, with the data of thermokinetic
experiments. The constant-volume combustion energy of the complex, Δc
U, was determined as being −17588.79 ± 8.62 kJ/mol by an RBC-II type rotatingbomb calorimeter at 298.15 K. Its standard enthalpy
of combustion, Δc
H
m
ϑ
, and standard enthalpy of formation, Δf
H
m
ϑ
, were calculated to be −17604.28 ± 8.62 and −282.43 ± 9.58 kJ/mol, respectively.
The text was submitted by the authors in English. 相似文献
203.
A series of samples with the composition Ca(1)(-)(x)Na(2)(x)Al(2)B(2)O(7) (0 < x < or = 1) was investigated and a hexagonal structure with unusually large range of homogeneity (at least from x = 0.01 to 0.95) was revealed. The hexagonal phase consists of [Al(2)B(2)O(7)](infinity)(2)(-) lamellae stacked along the c axis, as in CaAl(2)B(2)O(7) and Na(2)Al(2)B(2)O(7). Nevertheless, the configuration and stacking sequence of the [Al(2)B(2)O(7)](infinity)(2)(-) lamellae are different in these three structures. In the hexagonal structure of Ca(1)(-)(x)()Na(2)(x)()Al(2)B(2)O(7), Ca and half Na cations (Na1) statistically occupy the same crystallographic site which is located between the [Al(2)B(2)O(7)](infinity)(2)(-) lamellae, the other half Na cations (Na2) distribute in the planes bisecting the [Al(2)B(2)O(7)](infinity)(2)(-) lamellae. Depending on the composition, the site occupation factor of Na2 site can vary in the same range as x, leading to a tunable density of Na(+) vacancies in the structure. The AlO(4) tetrahedra and BO(3) triangles in the structure tilt in appropriate ways to improve the bond valence sum of Na2 cations which are not sufficiently bonded to the anions. 相似文献
204.
205.
206.
Biranje Santosh Shivaji Sun Jianzhong Shi Yifei Yu Sujie Jiao Haixin Zhang Meng Wang Qianqian Wang Jin Liu Jun 《Cellulose (London, England)》2021,28(14):8899-8937
Cellulose - Excessive hemorrhage is a leading cause of death to trauma patients, especially in combat and civilian accidents. The main priority in the medical treatment of trauma patients is to... 相似文献
207.
Meng Chen Heng Jiang Yafei Feng Yuren Wang 《Applied Physics A: Materials Science & Processing》2014,117(4):2067-2072
We experimentally and theoretically investigated the mechanisms of acoustic absorption in phononic glass to optimize its properties. First, we experimentally studied its locally resonant absorption mechanism. From these results, we attributed its strong sound attenuation to its locally resonant units and its broadband absorption to its networked structure. These experiments also indicated that the porosity and thickness of the phononic glass must be tuned to achieve the best sound absorption at given frequencies. Then, using lumped-mass methods, we studied how the absorption bandgaps of the phononic glass were affected by various factors, including the porosity and the properties of the coating materials. These calculations gave optimal ranges for selecting the porosity, modulus of the coating material, and ratio of the compliant coating to the stiff matrix to achieve absorption bandgaps in the range of 6–30 kHz. This paper provides guidelines for designing phononic glasses with proper structures and component materials to work in specific frequency ranges. 相似文献
208.
209.
ABSTRACTA homologous series of new chiral liquid crystal compounds, MnBEB (n = 4–10), was prepared by covalently linking a chiral (–)-menthyl with biphenyl-benzoate via a dicarboxylic spacer of varying length and parity. A combination of analysis methods, such as FT-IR, 1H NMR spectra, differential scanning calorimetry (DSC), polarised optical microscopy (POM) and X-ray diffraction was carried out to systematically investigate their phase structures and phase transition behaviours. The length and parity of the flexible spacers has a profound influence on the Tm and Tc and a modest odd-even effect is observed for the chiral liquid crystal compounds MnBEB. Only compound M4BEB developed an N* phase with selectively reflection on heating and a blue phase on cooling process. In addition, increasing the length of the flexible spacers tends to narrow the temperature range of the N* phase and widen the smectic phase, moreover, the pitch becomes longer with the spacer increases. 相似文献
210.