The crystal structures of the compounds show a packing of 1. New tetraazamacrocyclic ligands the macrocycles cyclen and cyclam 12anen 4 and 14anen 4 have been known for several decades, and their complexation chemistry with a large variety of metal ions has been studied thoroughly. Examples include photosynthesis, which proceeds due to the magnesium macrocycle chlorophyll, and various electron transfer reactions which occur in cytochromes. As such, these ligands are particularly useful in applications where robust transition metalphosphine complexes are employed, as in homogeneous catalysis or in radiopharmaceuticals.
The oxidation of cyclohexanone by the niiii complex of the macrocyclic ligand, 5,5,7,12,12,14hexamethyl1,4,8,11tetraazacyclotetradecanemeso14ane in acetonitrile solution containing cf 3 co 2 h obeyed the rate equation. This book contains an overview of the macrocyclic ligand systems and discusses the structure and properties of macrocyclic systems. In this paper, the synthesis and coordination chemistry of some macrocyclicbased tetranuclear metal complexes derived from the schiffbase na 4 l are investigated. Formation constants for complexion between alkali metal cations and the crown ether 18c6 in the solvent 2cyanopyridine at 3ooc were determined from conductance measurements. All except two au complexes were characterized using singlecrystal xray diffraction. The method also permits accurate evaluation of association equilibrium constants.
Lindoy, cambridge university press, cambridge, 1989. Field spectra and magnetic properties of synthetic macrocyclic complexes. Note in these figures that the coordinated macrocyclic and openchain complexes have been arbitrarily set at equal energies. As indicated in the figures, a free macrocyclic ligand in. Chemistry of dinucleating macrocyclic ligand and their complexes. Kinetic and spectral studies in the presence of cf 3 co 2 na indicate the inhibition term in cf 3.
Cambridge core molecular biology, biochemistry, and structural biology the chemistry of macrocyclic ligand complexes by l. The chemistry of macrocyclic ligand complexes cambridge texts. Electrochemical co2 and o2 reduction using nickel and. The study of macrocyclic ligand systems represents a major activity impinging on a wide range of areas in chemistry and biochemistry. The tlc of all the ligand and complexes confirmed their purity. Trivalent chromium, manganese and iron salts react in situ with 2,6diacetylpyridine and 1,2diaminobenzene to form complexes containing a 18membered. The chemistry of macrocyclic ligand complexes ebook, 1989. Chapter 1 provides an overview of metalcarboxamide and pyridinamide chemistry including a number of important pincer compounds, macrocyclic involvement in formation of metaltemplated rotaxanes and catenanes, oxidation catalysts, anion receptors and bimetallic complexes. What is different about macrocyclic ligand complexes. Macrocyclic chelators offer the benefit of high stability complex formation and, through functionalization, the opportunity to fine tune the coordination environment. Lindoy, the chemistry of macrocyclic ligand complexes, cambridge university press, cambridge 1989. Dicopper complexes of a macrocyclic ligand as models for. Such macrocyclic ligands often lead to complexes with enhanced thermodynamic and kinetic stability with respect to metal ion. Isbn 052125261x the study of macrocycles and their complexes has developed rapidly in recent years, coming of age with the award of the 1987 nobel prize in chemistry to three of its leading practitioners.
This chapter discusses the progress towards the synthesis of this ligand as well as design strategies. The selectivity of the macrocyclic ligands that contain combination of oxo o, aza n, phospha p and sulpha s for the extraction of metal ions depends on the ligand flexibility, nature of the ligand backbone, the cavity size of the macrocyclic core, nature and number of donor atoms in addition to their relative position in the macrocyclic. The magnesium complex 1 of the tetranucleating macrocyclic ligand h4l1 on transmetalation with copperii perchlorate in the presence of triethylamine produces the dicopperii complex 3 of the dinucleating macrocyclic ligand h2l3, while the same reaction when carried out in absence of triethylamine affords the metaldeficient compound 4 derived from h2l3. Synthesis and reactivity in inorganic and metalorganic chemistry, vol. The study of metal complexes of macrocyclic ligands appears to. Metal complexes of acyclic and macrocyclic multifunctional ligands. The study of macrocyclic chemistry represents a major area of activity which impinges on a range of other areas in. Canadian journal of chemistry canadian science publishing. Synthesis and characterization of complex compounds of.
Preparation of macrocyclic complexes the ability of certain transition metals, especially nickel, to act as a template in intermolecular schiffbase reactions into macrocycle formation is well known3, 4. Macrocyclic ligands that can incorporate two or more metal ions giving homo or heterodinuclear complexes are of considerable interest. Some other common chelating and cyclic ligands are shown below. Biomedical applications of macrocyclic ligand complexes. Synthesis and characterization of complex 1051 figure 1. The chemistry of macrocyclic ligand complexes by l. Synthesis of nnnn tetradentate macrocyclic ligand and its. Cucurbituril as a new macrocyclic ligand for complexation. Some of these heterodinuclear complexes are interesting as they mimic the active sites of metalloenzymes, such as cytochromec oxidase and bovine erythrocyte superoxide dismutase. This idea is further supported by the presence of a broad ligand.
Three novel complexes of cuii, coii and znii using macrocyclic ligand derived by the condensation of diethyl phthalate and. Coordination chemistry of macrocyclic compounds edwin c. Synthesis and coordination chemistry of macrocyclic phosphine. Synthetic strategies toward sterically demanding macrocyclic ligands in order to prevent the formation of iron complexes of nuclearity higher than 2, a picketfence macrocyclic ligand, h2tipp4pim was designed. Synthesis and characterization of ironiii, cobaltii and nickelii metal complexes with tahhdap and tahhtda hexadentate macrocyclic ligands.
A template approach was used to prepare the ligand in a reasonable yield. Density functional calculations are used to elucidate the reaction mechanism of water oxidation catalyzed by iron tetraamido macrocyclic ligand taml complexes. In particular, they are capable of stabilizing boxlike structures such as syn. It covers the common types and the main strategies for the synthesis of. Leonard f lindoy this book contains an overview of complex formation by macrocyclic ligand systems. Coordination chemistry of macrocyclic compounds gordon. This book describes the coordination chemistry of macrocyclic ligands. The macrocyclic ligand c 16 h 38 n 4 o 2 br 2 4was synthesised by mixingammonium salt0. The crystal and molecular structure of lcu2ch3co22clo425h2o. The first example of cobalt dimethylisocorrole was also demonstrated. Research in medicinal inorganic chemistry has expanded in recent years by exploiting a variety of chelating ligands to modify and control the properties of metal ions in biological systems. Macrocyclic compounds have attracted increasing interest owing to their mixed softhard donor character, versatile coordination behavior and in the understanding of molecular processes.
The study of macrocyclic chemistry represents a major area of activity which impinges on a range of other areas in both chemistry and biochemistry. The formation of ln 4 complexes results from the combined influence of the tetradentate coordination of the polycation by the portals of the macrocyclic ligand cb6 and the chelating effect of the carboxylate ligands of isonicotinic acid generated as a result of hydrolysis of 4. Macrocyclic phosphine compounds are sought after as ligands for transition metal complexes because of their strong binding properties. This popularity may be due to the complexes high thermodynamic stability, relative kinetic inertness, basicity, transition metalion coordinating ability, and rigid structure 6. Tetranuclear lanthanide aqua hydroxo complexes with. G always favours formation of macrocyclic complex log k 1 23. Coordination chemistry of macrocyclic compounds springerlink. The method allows for precise determination of these formation constants up to values of kf. Synthesis and coordination chemistry of macrocyclic. Synthesis of nnnn tetradentate macrocyclic ligand and its pdii, ptii, ruiii, and iriii complexes. The polynuclear complexes mo 3 o 8 tidfdmso2h 2 o 1 and cu 2 tidf 2. A lanthanide metalorganic framework based on a custom.
The energetic basis for the macrocyclic effect can be most easily understood by comparing the relative stabilities of unbound macrocyclic ligands to openchain ligands as illustrated in fig. Mobilities of cationmacrocyclic ligand complexes 1535 in eq. Metal complexes of acyclic and macrocyclic multifunctional. This book contains an overview of complex formation by macrocyclic ligand systems. Coordination chemistry of macrocyclic ligands request pdf. The chemistry of macrocyclic ligand complexes edited by l. The fact that macrocyclic ligand complexes are involved in a number of fundamental biological systems has long been recognized. Current trends and future perspectives illustrates essential concepts in this expanding research field covering both basic and applied studies. Generally, macrocyclic polyamides are prepared by reaction of polyamine with either the diester salt of dicarboxylic acid or the dicarboxylicacid dichloride 24. A cyclic macromolecule has no endgroups but may nevertheless be regarded as a chain. Fenton and others published the chemistry of macrocyclic ligand complexes edited by l. The unique photophysical and redox properties of the complexes were shown due to great metal ligand cooperativity by dft and tddft calculations. Since its birth, the development of macrocyclic chemistry has proceeded along two lines. The chemistry of macrocyclic ligand complexes cambridge.
Stoichiometric and metaldeficient copperii complexes of. These new tetrapyrrole nickel and cobalt complexes display strong light absorptivity and rich multielectron redox chemistry. Written by wellknown experts from around the world, the topics of the chapters range. Ir spectra of macrocyclic ligand and its complex pdl 1h nmr spectra the 1hnmr spectrum of the macrocyclic ligand shows triplet in the region. Chemistry of dinucleating macrocyclic ligand and their. The chemistry of macrocyclic ligands has been known for several decades 1.
Synthesis of 14membered tetraazamacrocyclic ligand. Electrochemical studies of synthetic models of copper proteins. Synthesis, characterization and biological screening of some schiff. Magnetostructural correlation of the fe ii, co ii and ni ii complexes with l and with previously studied structurally similar ligands revealed a significant impact of the functional group in pendant arms on the magnetic anisotropy especially that of the co ii and ni ii complexes and some recommendations concerning the ligandfield design. The text discusses the structures and properties of macrocyclic. Three new complexes niii, cuii and coii were synthesized of macrocyclic ligand derived from 1, 4dicarbonylphenyldihydrazide and ophthalaldehyde in the ratio of 2. Get your kindle here, or download a free kindle reading app. The field has characteristically yielded many interesting and unusual compounds. The synthesis of compounds which may serve as model systems for some natural products containing large rings as ligands provided the main goal for the early expansion of research effort. Metal complexes of ditopic and polytopic macrocyclic ligands. Stable octahedral, lowspin nickeliii complexes of a. An overview of essential concepts in supramolecular chemistry covering basic and applied reseach work. In chemistry, a macrocyclic ligand is a macrocycle with a ring size of at least nine including all hetero atoms and three or more donor sites. Of the many macrocyclic template reactions, the preparation of geodkens macrocycle 2 is particularly attractive6 for the.
Macrocyclic ligands exhibit particularly high affinity for metal ions. Metal complexes of macrocyclic ligands containing pyridine. Macrocyclic ligand complexes are involved in a variety of fundamental biological systems. Synthesis of 12membered tetraaza macrocyclic pyridinophanes bearing electronwithdrawing groups. Nature chooses macrocyclic derivatives which give enhanced kinetic and thermodynamic stabilities, such that the metal ion. Diffraction results have yielded three molecular structures, cd12ane. Synthesis and reactivity in inorganic, metalorganic, and nanometal chemistry. Fourteen agi, aui, niii, pdii, and ptii complexes with macrocyclic tetradentate nheterocyclic carbene nhc ligands were prepared via reactions between three macrocyclic tetrabenzimidazolium salts and metal precursors. Polyazamacrocycles represent a popular class of macrocyclic ligands for supramolecular chemistry and crystal engineering. Synthesis and structural characterization of metal. Binuclear complexes of a new hexadentate macrocyclic ligand.
Synthesis, characterization, and antibacterial activity of. Distinctive coordination chemistry and biological significance of complexes with macrocyclic ligands. The importance of such complexes, for example to the mechanism of photosynthesis, or to the transport of oxygen in mammalian and other respiratory systems, has provided a motivation for investigation of the metalion. Toxic metal complexes of macrocyclic cyclen molecule.
184 1176 1485 124 523 637 705 722 1270 1607 932 1354 958 811 860 1261 1050 837 691 1242 1605 537 1432 1428 1131 1300 222 1307 151 1310 675 279 924 1369 153 1051 213 1063 1114 400 144 379