Wyniki wyszukiwania - BazTech

1

Kwas hypodifosforowy i jego sole nieorganiczne

Kinzhybalo Vasyl, Otręba Marta, Ślepokura Katarzyna, Lis Tadeusz

Wiadomości Chemiczne

|

2021

|

[Z] 75, 3-4

423--466

EN

Hypodiphosphoric acid is the lower oxoacid of phosphorus of H4P2O6 composition. It contains the direct P—P bond, in contrast to its closest analog - pyrophosphoric acid, H4P2O7. In comparison to other phosphates the knowledge on hypodiphosphoric acid and its inorganic salts is quite limited. Since its discovery almost 150 years ago, establishment of the proper molecular and structural formula of the acid has initiated intensive research and dispute in the literature, which was decisively ended in 1964, when the first complete X-ray crystal structure determination of diammonium hypodiphosphate was reported. Since then structural studies have led to the discovery of ferroelectric properties in the above-mentioned diammonium salt and dehydration-induced staggerer-eclipsed transformation of hypodiphosphate in tetrabutylammonium salt, experimental electron density distribution determination in cubic tetralithium hexahydrate and last but not least crystal structure elucidation of hypodiphosphate analogs of adenosine diphosphate. In this mini-review the information on synthesis techniques, chemical and physical properties, applications of hypodiphosphates along with crystallochemical description of reported up-to-date crystal structures are presented.

2

Sieci metalo-organiczne jako multifunkcjonalne materiały przyszłości : mechanochemiczne podejście do syntezy

Jędrzejowski D.

Wiadomości Chemiczne

|

2018

|

[Z] 72, 9-10

645--666

EN

Metal-organic frameworks (MOFs) are a relatively new class of advanced inorganic-organic materials. Due to their modular structures and possible incorporation of various properties, that materials find more and more applications in many fields of science and industry. MOFs are coordination polymers, i.e. compounds with coordination bonds propagating infinitely in at least one dimension. Their characteristic feature is the presence of potential free spaces, i.e. pores. The free spaces often appear after proper activation, e.g. thermal activation. Other common properties of MOFs include for instance large specific surface areas and pore volumes, modifiable size and chemical environment of the pores, and network flexibility. All these properties result in the use of MOFs in e.g. selective sorption, separation or storage of gases, heterogeneous catalysis, design and fabrication of sensors, etc. During more than twenty years of the history of MOFs, many methods of their synthesis have been developed, including the most popular in solution at elevated temperatures (e.g. solvothermal method). Nevertheless, the activity of pro-ecological environments and the requirements set by international organizations encourage scientists to create new methods of synthesis, which, according to the guidelines presented by the 12 principles of green chemistry, will be safer, less aggressive, less toxic and less energy-consuming. One of the answers to meet these requirements is the use of mechanosynthesis. Mechanochemical synthesis relies on the supply of energy to a system by mechanical force, by grinding or milling. By combining or transforming solids in this way, the presence of a solvent, which is most often the main source of contamination and waste, can be minimised or completely excluded. Mechanical force is typically used for purposes other than MOF synthesis, e. g. catalyst grinding. Nevertheless, the use of mechanical force in synthesis is becoming more and more popular. The most important advantages of this approach, apart from its environmental impact, are very high efficiency (usually close to 100%) and drastically reduced reaction time. Of course, there are examples where these advantages are not observed. In such cases, mechanosynthetic modifications are introduced, such as e.g. addition of small amount of liquid (Liquid-Assisted Grinding) and/or a small addition of simple inorganic salt (Ion- and Liquid-Assisted Grinding). Furthermore, new instrument setups are being developed to monitor reaction mixtures in situ during mechanosynthesis, e.g. by use of such techniques as powder X-ray diffraction and Raman spectroscopy. This enables valuable insights into mechanisms and allows for mechanosynthesis optimization.

3

Zasady Schiffa – interesujący zakres zastosowań w różnych dziedzinach nauki

Brodowska K., Łodyga-Chruścińska E.

Chemik

|

2014

|

Vol. 68, nr 2

129--134

PL

Kompleksy metali odgrywają istotną rolę zarówno w rolnictwie, jak również chemii farmaceutycznej i przemysłowej. Zasady Schiffa są produktami kondensacji pierwszorzędowych amin i związków karbonylowych. Związki te oraz ich kompleksy z metalami są coraz częściej stosowane jako katalizatory, polimery i barwniki. W artykule przedstawiono właściwości zasad Schiffa oraz korzyści wynikające z ich stosowania w różnych gałęziach przemysłu.

EN

Metal complexes play an important role in agriculture as well as industrial and pharmaceutical chemistry. Schiff bases are the condensation products of primary amines and carbonyl compounds. Schiff bases and their metal complexes are increasingly being used as catalysts, polymers and dyes. This paper reviews the properties of Schiff bases and benefits of their use in various branches of industry.

4

Architektury supramolekularne jako wynik samoorganizacji w kompleksach jonów metali d- i f- elektronowych

Patroniak V.

Wiadomości Chemiczne

|

2010

|

[Z] 64, 3-4

285-318

EN

The use of transition metal complexes of bridging multidentate ligands to construct predictable, self-assembled small inorganic systems and multi-dimensional infinite networks is an area of chemistry which has received ever-increasing attention over the recent years. Self-organization occurs usually from a mixture of components (organic ligands, salt crystals, and sometimes solvent molecules). The products exhibit a notable thermodynamic and kinetic stability and their components should contain all the information necessary for a correct assembly to occur [1–6]. Self-assembly has recently been studied in many types of organic and inorganic systems. This latter approach has proven particularly successful for the generation of a wide spectrum of architectural topologies such as for example, helicates [7–11], rotaxanes [12, 13], clusters [14–16], ladders [17–19], cages [20–22], grids [23–25] and molecular wheels [26–28], etc., based on ligand design and an application of suitable coordination geometries for the assembling system. The structure of supramolecular complexes depends strongly on the ligand substituent, the ligand conformation, the metal ion, the counterion, the solvent, and the reaction conditions [29–37]. Such compounds may exhibit novel physical and chemical properties with a potential use in supramolecular engineering, nanotechnology, biomedical inorganic chemistry, biological catalysis, and in the area of sensors [38–46]. The review has been prepared on the results of my own studies in the field [47–59] and focused on structural diversity and characterization of supramolecular complexes. The architectures of these compounds generated by self-assembly of polypirydyl ligands with d-and f-metal ions are fascinating and attractive because of their unusual properties and prospective implementation in many application [60–74].

5

Soil-biosphere interactions

Franzle S.

Proceedings of ECOpole

|

2007

|

Vol. 1, No. 1/2

23--35

EN

Soil is more than a source of nutrients and water and a solid support for plants, animals, fungi, bacteria... which live in or on it. The organisms rather change the biogcochemical features of soils especially as far as mobility and thus bioavailability vs. retention of essential and other metal ions are concerned. The interactions among soil and soil-dwellers to change living conditions in contact to soil account for phenomena of succession as well as for competition or changes in (net) primary productivity of a given area over time; there is a general trend of chemical development counter-acted by earthworms and some fungi only: the most stable compounds in soil (polyphenols) retain iron and copper to impede fungal growth. By means of the relationship between metal complex stabilities, bioconcentration factors and the electrochemical ligand parameter developed by this author, corresponding data for biorelevant ligands and such concerning eg REE (rare earth elements) and Al partition (partition coefficients used as a kind of benchmark) between soil and organisms can be combined to identify both the present state of some soil and the possible or additional risks imposed by deliberate measures such as liming and by ongoing soil burdening (eg due to acid rain).

PL

Gleba jest czymś więcej niż tylko źródłem substancji odżywczych oraz wody i miejscem życia dla roślin, zwierząt, grzybów i bakterii, które żyją w niej lub na niej. Organizmy mają wpływ na biogeochemiczne właściwości gleby, zwłaszcza na mobilność, a przez to na biologiczną dostępność oraz zatrzymywanie substancji niezbędnych i innych jonów metali. Oddziaływanie pomiędzy glebą a organizmami glebowymi może prowadzić do zmiany ich warunków życia i produktywności gleb oraz może prowadzić do rywalizacji; jest to ogólny trend przemian chemicznych, któremu przeciwdziałają dżdżownice oraz niektóre grzyby: najbardziej trwałe w glebie związki (polifenole) zatrzymują żelazo i miedź, co hamuje wzrost grzybów. Relacje między stabilnościami kompleksów metali, biokoncentracją metali i elektrochemicznymi parametrami ligandów np. REE (metali ziem rzadkich) i Al mogą być wykorzystane do opisu obecnego stanu gleby oraz jego zmiany i możliwego albo dodatkowego ryzyka związanego np. z wapnowaniem i rosnącym obciążeniem gleby (np. z powodu kwaśnych deszczy).

6

What does bioaccumulation really tell us? - analytical data in their natural environment

Fränzle S., Markert B.

Chemia i Inżynieria Ekologiczna

|

2007

|

Vol. 14, nr 1

7-23

EN

Analytical data on biological materials will not give information on the environment the samples were taken from directly. Rather, the analyzed components underwent bioconcentration or the reverse during uptake in the plant or animal. For metal ions, bioconcentration or - dilution will be related to the coordination (ligation) properties of the metal ions since far less ligands are used to sequester metals than there arc elements in the surroundings, hence one ligand interacts with many different metals. A novel method is outlined to describe metal properties in coordination chemistry by two typical parameters, c and x. From this a term is calculated which compares the relative bioconcentration properties of specified biomass, eg leaves of birch, to binding selectivities of some equivalent ligand. Thus bioconcentration of yet other metal ions by the corresponding organism can be predicted. Examples are given for aquatic plants. Moreover, real sequestering ligands and equivalent-ligand behaviours for key components of forest flora arc given in diagrams which also depict the mathematical line of reasoning. Combining these steps allows for a"weighted" treatment of bioconcentration and thus eventually an extrapolation on the status of ambient water or groundwater. Only after this transformation of data was done, rational biomonitoring including comparisons among different sympatric species becomes feasible.

PL

Dane analityczne bezpośrednio pobranych próbek materiału biologicznego nic dają pełnych informacji o środowisku. Pełniejszy obraz stanu środowiska daje analiza biokoncentracji lub efekt przeciwny zanieczyszczeń w organizmach roślinnych i zwierzęcych. Dla jonów metalu stopień biokoncentracji jest związany z właściwościami koordynacyjnymi jonu, a jeden ligand oddziałuje z wieloma różnymi metalami. Nowym podejściem w chemii koordynacji jest opisanie właściwości metalu za pomocą dwóch charakterystycznych parametrów, e i x. Na ich podstawie oblicza się wielkość, która porównuje względne właściwości biokoncentracyjne określonej biomasy, np.: liści brzozowej w powiązaniu z równoważnie selektywnym ligandem. W ten sposób można przewidzieć biokonccntrację innych jonów metali w organizmach. Jako przykłady wymieniono niektóre rośliny wodne. Porównano zachowania rzeczywistych ligandów występujących w kluczowych składnikach flory leśnej i ligandów równoważnych. Takie podejście umożliwia wykorzystywanie stopnia biokoncentracji do opisu stanu wód naturalnych lub wody gruntowej. Tylko po takim przekształceniu danych jest możliwy racjonalny biomonitoring, włączając porównania pośród różnymi gatunkami.

7

Właściwości koordynacyjne ligandów z ugrupowaniem fosfonowym z wybranymi jonami metali

Kamecka A., Kurzak B.

Wiadomości Chemiczne

|

2003

|

[Z] 57, 9-10

797--825

EN

Aminopolyphosphonic acids and their derivatives have received considerable attention because of their interesting biological activity and a wide range of uses for industrial, chemical, agricultural and pharmacological purposes. The area of metal phosphonate chemistry has developed significantly in the last three decade. The coordination chemistry of this group of ligands is rich due to their versatility in adopting monodentate, bridging and chelating modes of coordination. Phosphonates and aminophosphonates are potent chelating agents for variety metal ions including the alkaline earth ions, the divalent ions as well as the trivalent ions. In this article we are summarizing and discussing the acid-base properties and the metal ion-coordinating properties of compounds involving one, two or more phosphonic groups. This work is aimed at being brief indicating the main achievements in researches over coordination preferences of this group of ligands. The present considerations are restricted to complexes in solution, involving the alkaline earth ions and the divalent ions of the second half of the 3d series as well as Zn2+ and Cd2+. The acid-base properties of the considered ligands depend on many factors such as the number of phosphonic groups in one molecule, the presence of other functional groups (e.g. COOH, NH3+, OH), the distance between functional groups and electronic effects of the substituents. These ligands contain a range of potential donor atoms. As a result, various bonding modes for a given chelating ligand are involved, and are reviewed with reference to ligand structure and the resulting coordination complexes. It is shown that depending on the pH and the nature of the metal ion in solution these ligands can bind to a metal ion via oxygen(s) (mostly with alkaline earth ions), and in a N,O bonding mode (usually with d metals). Coordination properties of phosphonic and aminophosphonic acids are important factors to understand the role of the ligands and metal ions in biological systems.

8

Sposoby koordynacji grupy karboksylanowej w kompleksach metali z kwasami karboksylowymi

Brzyska W.

LAB Laboratoria, Aparatura, Badania

|

2002

|

R. 7, nr 1

20-23

PL

Chemia koordynacyjna jest dyscypliną, która stopniowo wyodrębniła się z chemii nieorganicznej i obecnie rozwija się bardzo dynamicznie. Większość bowiem związków metali to związki kompleksowe, które w swej budowie zawierają zarówno ligandy nieorganiczne, jak i organiczne.

9

Coordination chemistry of Mo(IV) and W(IV) based on tetracyanodioxo precursors

Samotus A., Szklarzewicz J., Matoga D.

Bulletin of the Polish Academy of Sciences. Chemistry

|

2002

|

Vol. 50, No. 2

145-164

EN

The substitution reactions of [M(CN)(4)O(H(2)O)](2-) (M = Mo, W) used as starting material are described. The chemistry of complexes of the type [M(CN)4O(L)](n-), [M(CN)(3)O(LL)](n-) and [Mo(CN)(2)O(LLLL)] is discussed, basing on their structures and spectroscopic properties.

10

Early transition metal complexes containing aminopyridinato ligands - coordination chemistry, organometallic chemistry and catalysis

Kempe R., Oberthur M., Hillebrand G., Spannenberg A., Fuhrmann H.

Polimery

|

1998

|

T. 43, nr 2

96-104

EN

Early transition metal complexes containing aminopyridinato ligands have been reported only rarely. Such ligands combine a number of virtues which make them unique in the early transition metal chemistry. Besides the great variety of substitution patterns enabling us to fine tune electronic and steric features, they impress us with the flexibility in the bind-ing mode covering the whole range from a pure amido metal bond up to a delocalized Namido-Cipso-Npyridine-M four members ring. Coordination chemistry, organometallic chemistry and some selected applications in homo-geneous catalysis including olefin polymerization are reviewed.

PL

Przedstawiono przegląd problemów chemii koordyjacyjnej wymienionych w tytule kompleksów metali przejściowych grup 3-6 skoordynowanych z atomami azotu oraz problemów chemii związków metaloorganicznych w odniesieniu do kompleksów metali grupy 3 i 4 z ligandami aminopirydynatowymi. Scharakteryzowano też przebieg katalizowanych przez omawiane kompleksy polimeryzacji olefin z zastosowaniem różnych kokatalizatorów glinoorganicznych (metyloaluminoksanu, i-Bu3Al, Et3Al2Cl3) oraz polimeryzacji z otwarciem pierścienia laktamów.