Synthesis and and characterization o f of inorganic inor complexes p

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1 Synthesis and characterization of inorganic complexes

2 Direct Synthesis methods

3 Direct synthesis of coordination and organomtallic compounds Alexander D. Garnovskii Boris I. Kharisov 3 SYNTHESIS AND CHARAC CTERIZAT TION OF INORGANIC COMP PLEXES

4 "direct synthesis" of metal complexes starting from metal vapors in the gas phase. Direct methods: 1 Cryosynthesis of metal complexes 2 Direct electrosynthesis of metal complexes 3 Oidti Oxidative dissolution of metals tl and metal tloxides in a liquid phase 4 Mechanosynthesis of coordination compounds 4 SYNTHESIS AND CHARAC CTERIZAT TION OF INORGAN NIC COMP PLEXES

5 SYNTHESIS AND CHARACTERIZATION OF INORGANIC COMPLEXES 5 Cryosynthesis of metal complexes

6 Cryosynthesis of metal complexes A gaseous atom of any element except the noble gases may be expected to be more reactive than the normal form of the element for two reasons. A) the atom can react faster because it has minimal steric requirements and generally has readily available electrons or orbitals. B) the atom is a species of higher energy than the normal state of the element (for the heats of formation of the elements 6 SYNTHESIS AND CHARAC CTERIZATION OF INORGAN NIC COMP PLEXES

7 Cryosynthesis of metal complexes This method limitation is the instability of complexes at high temperatures. Temperature e rang: g:usually 10 to 273 K K condensed Metal (solid) Metal (gas) Ligand vacuum Reaction low temperature 7 SYNTHESIS AND CHARAC CTERIZAT TION OF INORGAN NIC COMP PLEXES

8 Cryosynthesis of metal complexes Vaporization methods: resistive heating induction heating bombardment with electrons of a few Kilovolts cathodic sputtering laser irradiation. 8 SYNTH HESIS AND CHARAC CTERIZAT TION OF INORGANIC COMP PLEXES

9 SYNTHESIS AND CHARACTERIZATION OF INORGANIC COMPLEXES Cryosynthesis of metal complexes نيم سال اول

10 SYNTHESIS AND CHARACTERIZATION OF INORGANIC COMPLEXES 10 Cryosynthesis of metal complexes electron beam vaporization

11 SYNTHESIS AND CHARACTERIZATION OF INORGANIC COMPLEXES 11 Cryosynthesis of metal complexes laser vaporization

12 SYNTHESIS AND CHARACTERIZATION OF INORGANIC COMPLEXES Cryosynthesis of metal complexes 12 solution metal-atom atom reactor

13 Cryosynthesis of metal complexes Transformations in this method: σ- and π-coordination of metal atoms Insertion of metals into a C-X bond (X = H, Hal) 13 SYNTHESIS AND CHARAC CTERIZAT TION OF INORGANIC COMP PLEXES

14 Cryosynthesis of metal complexes Synthesis of metal complexes with simple inorganic ligands 14 SYNTHESIS AND CHARACTERIZATION OF INORGANIC COMP PLEXES

15 Cryosynthesis of metal complexes It is necessary to mention that the well-known nickel tetracarbonyl, obtained more than 100 years ago by the reaction between the bulk metal and CO, can also be synthesized by the unusual direct interaction between nickel vapor and CO 2 (as well as swith CO) in a yedo yield of--~10% 15 SYNTHESIS AND CHARAC CTERIZAT TION OF INORGANIC COMP PLEXES

16 Cryosynthesis of metal complexes Cryosynthesis of metal σ- and π-complexes Interaction of metals with olefins Interaction of metals with polyenes Interaction of metals with arenes and hetarenes Interaction of metals with alkynes Interaction ti of metals with other ligands Interaction of metal with polymers SYNTHESIS AND CHARAC CTERIZAT TION OF 16 INORGANIC COMP PLEXES

17 Cryosynthesis of metal complexes Cryosynthesis of metal σ- and π-complexes Interaction o f metals with olefins 17 SYNTH HESIS AND CHARACTERIZATION OF INORGANIC COMP PLEXES

18 Cryosynthesis of metal complexes Cryosynthesis of metal σ- and π-complexes Interaction of metals with polyenes 18 SYNTH HESIS AND CHARACTERIZATION OF INORGANIC COMP PLEXES

19 Cryosynthesis of metal complexes Cryosynthesis of metal σ- and π-complexes Interaction o f metals with arenes and hetarenes 19 SYNTH HESIS AND CHARACTERIZATION OF INORGANIC COMP PLEXES

20 Cryosynthesis of metal complexes Cryosynthesis of metal σ- and π-complexes Interaction o f metals with alkynes 20 SYNTH HESIS AND CHARACTERIZATION OF INORGANIC COMP PLEXES

21 Cryosynthesis of metal complexes Cryosynthesis of metal σ- and π-complexes Interaction of metals with other ligands Complexes obtained from atomic metals and oxygencontaining ligands 21 SYNTH HESIS AND CHARAC CTERIZATION OF INORGANIC COMP PLEXES

22 Cryosynthesis of metal complexes Cryosynthesis of metal σ- and π-complexes Interaction of metals with polymers 22 SYNTH HESIS AND CHARACTERIZATION OF INORGANIC COMP PLEXES

23 Cryosynthesis of metal complexes Vapor synthesis of metal chelates hlt The cryosyntheses y of metal acetylacetonates with the general formula M(acac) 2, where M= Mn, Cr, Fe, Ni, Pd, Cu, Zn, Sn, Pb, and M(acac) 3, where M = A1, Cr, Fe, Dy, Ho, Er, 23 SYNTH HESIS AND CHARAC CTERIZATION OF INORGANIC COMP PLEXES

24 Direct methods: 1 Cryosynthesis of metal complexes 2 Direct electrosynthesis of metal complexes 3 Oxidative dissolution of metals and metal oxides in a liquid phase 4 Mechanosynthesis of coordination compounds SYNTHESIS AND CHARAC CTERIZAT TION OF 24 INORGANIC COMP PLEXES

25 Direct Electrosynthesis of Metal Complexes Direct electrosynthesis of metal complexes The oldest method Synthesis complex from zero-valent metals. Gerdes (1882) platinum(iv) hexaaminates (anodic dissolution of a platinum electrode in a solution of ammonium carbonate) Chugaev (1908) The systematic study of electrosynthesis in coordination i chemistry ([C0(NH 3 ) 6 ]C1 3 [Co(NH 3 ) 4 C1]SO 4 [Co(NH 3 ) 4 (NO 2 ) 2 ]NO 3 ) cobalt anode and a platinum cathode; 25 SYNTHESIS AND CHARAC CTERIZAT TION OF INORGAN NIC COMP PLEXES

26 Direct Electrosynthesis of Metal Complexes Practical aspects Electrosynthesis is the optimal method for carrying out redox reactions, because it works at normal temperature. Advantages: - The addition of redox species to the reaction mixture is unnecessary. - Compounds are produced by metal dissolution in soft conditions and with very simple equipment, independently of the metal being anode or cathode. - It is possible to produce compounds which are very difficult to obtain by the classical route, especially those with the lowest metal oxidation state. This product selectivity, especially in organic electrosynthesis, demonstrates the power of electrochemistry. 26 The electrosynthesized compounds are sometimes more SYNTHESIS AND CHARAC CTERIZAT TION OF INORGAN NIC COMP PLEXES

27 Direct Electrosynthesis of Metal Complexes Advantages: - The electrosynthesized compounds are sometimes more reactive than those obtained by conventional methods. - The working conditions required to obtain the electrodic reactions permit minimum contamination as a consequence of the low amounts of gases liberated, and avoid the danger of explosion during the electrolytic process. Frequently, the electrochemical methods are carried out under milder conditions and at lower temperatures, leading to fewer reaction byproducts. -At present prices of metals are lower than those of their compounds. 27 SYNTHESIS AND CHARAC CTERIZAT TION OF INORGAN NIC COMP PLEXES

28 Direct Electrosynthesis of Metal Complexes Advantages: - The use of a metallic salt to produce a coordination compound implies the presence of anion forming the salt. When the process is carried out in the conventional way (from metal salts MX and organic ligands HL), it is possible to obtain the complexes MLX instead of desirable product MLn. The salt anion can participate in the formation of undesirable products. - the electrolytical method makes it possible to obtain compounds with a higher metal oxidation state whenever the substitution of the sacrificial anode by a platinum electrode is possible. 28 SYNTHESIS AND CHARAC CTERIZAT TION OF INORGAN NIC COMP PLEXES

29 Direct Electrosynthesis of Metal Complexes The application of direct electrosynthesis at an industrial level requires consideration of many factors: The availability and price of the starting material. The quantity of product obtained. The type and quantity of secondary products The price of the product isolated from the electrolytic medium. The maximum cell current The chemical and electrochemical stability of the electrolytic medium. The cell price 29 SYNTHESIS AND CHARACTERIZAT TION OF INORGAN NIC COMP PLEXES

30 Direct Electrosynthesis of Metal Complexes Experimental parameters: -The electrode potential. -The electrode material. -The solvent and supporting electrolyte. -The concentration of the electroactive species. -The ph and concentration of all species that can react with the intermediates. -The temperature and pressure. -The mass-transport regime, which influences the maximum current density, the intermediate product velocities and the amount of the mixture between the reaction layer and the bulk solution. The masstransport regime is determined by the electrolytic flow velocity and the movement of the electrodes. -The geometrical form of the electrodes and the presence or absence of separators or membranes. 30 SYNTH HESIS AND CHARAC CTERIZAT TION OF INORGAN NIC COMP PLEXES

31 Direct Electrosynthesis of Metal Complexes Solvent and supporting electrolyte Important points to select solvent: -The solubility of the electroactive species and supporting electrolyte. - Poor (or no) reactivity to the products. - Facility of purification. - Stability to the applied potential gradient of approximately 20 V cm Dielectric constant values. - Low viscosity (especially if fast transport to electrodes is necessary). - Adequate volatility to facilitate its elimination. - Easy separation by precipitation of the product from the solvent. 31 SYNTH HESIS AND CHARAC CTERIZAT TION OF INORGAN NIC COMP PLEXES

32 Direct Electrosynthesis of Metal Complexes standard dsolvents: alcohols tetrahydrofuran (THF) dimethylformamide (DMF) dimethyl sulfoxide (DMSO) acetonitrile (AN) pyridine (Py) SYNTH HESIS AND CHARAC CTERIZAT TION OF such exotic solvents as propylene carbonate sulfolane diglyme hexamethylphosphortriamide h h t id 32 INORGAN NIC COMP PLEXES

33 Direct Electrosynthesis of Metal Complexes Types of cells Undivided cell and divided cell Undivided cells have less resistance than divided ones 33 SYNTHESIS AND CHARACTERIZAT TION OF INORGANIC COMP PLEXES

34 93-92 ﻧﻴﻢ ﺳﺎل اول 34 SYNTH HESIS AND D CHARAC CTERIZAT TION OF INORGAN NIC COMP PLEXES Direct Electrosynthesis of Metal Complexes

35 Direct Electrosynthesis of Metal Complexes Electrolytic parameters Using a current range of ma The voltage required to obtain this current typicallyranges from 10 to 50 V The electrosynthesis of coordination compounds is carried out by using a sacrificial anode or cathode 35 SYNTHESIS AND CHARAC CTERIZAT TION OF INORGAN NIC COMP PLEXES

group (E = NR, O, S, Se) take part in the process of

36 Direct Electrosynthesis of Metal Complexes Reactions: Reactions under solvation conditions If ligands (LH) with an acidic EH group (E = NR, O, S, Se) take part in the process of electrosynthesis 36 SYNTHESIS AND CHARACTERIZAT TION OF INORGAN NIC COMP PLEXES

37 Direct Electrosynthesis of Metal Complexes Electrosynthesis at sacrificial anodes Electrosynthesis of molecular complexes (adducts) Electrosynthesis of metal chelates Electrosynthesis of di- and polymetallic complexes Electrosynthesis of σ- and π-organometallic complexes Electrosynthesis at sacrificial cathodes 37 SYNTHESIS AND CHARACTERIZAT TION OF INORGAN NIC COMP PLEXES

38 Direct Electrosynthesis of Metal Complexes Electrosynthesis at sacrificial anodes Electrosynthesis of molecular complexes (adducts) 38 SYNTHESIS AND CHARACTERIZATION OF INORGANIC COMP PLEXES

39 Direct Electrosynthesis of Metal Complexes Electrosynthesis at sacrificial anodes Electrosynthesis of molecular complexes (adducts) 39 SYNTHESIS AND CHARACTERIZATION OF INORGANIC COMP PLEXES

40 SYNTHESIS AND CHARACTERIZATION OF INORGANIC COMPLEXES Direct Electrosynthesis of Metal Complexes نيم سال اول

41 Direct Electrosynthesis of Metal Complexes Electrosynthesis at sacrificial anodes Electrosynthesis of metal chelates some chelate-forming ligands, such as dimethylglyoxime, β-diketones, azomethines, oxyphenylazoles, SYNTHESIS AND CHARAC CTERIZAT TION OF 41 INORGANIC COMP PLEXES

42 SYNTHESIS AND CHARACTERIZATION OF INORGANIC COMPLEXES Direct Electrosynthesis of Metal Complexes نيم سال اول

43 SYNTHESIS AND CHARACTERIZATION OF INORGANIC COMPLEXES Direct Electrosynthesis of Metal Complexes نيم سال اول

complexes Few publications The cadmium complex of composition

44 Direct Electrosynthesis of Metal Complexes Electrosynthesis at sacrificial anodes Electrosynthesis of di- and polymetallic complexes Few publications The cadmium complex of composition CdL 2 44 SYNTHESIS AND CHARAC CTERIZAT TION OF INORGANIC COMP PLEXES

45 Direct Electrosynthesis of Metal Complexes Electrosynthesis at sacrificial anodes Electrosynthesis of σ- and π-organometallic complexes 45 SYNTHESIS AND CHARACTERIZATION OF INORGANIC COMP PLEXES

46 SYNTHESIS AND CHARACTERIZATION OF INORGANIC COMPLEXES Direct Electrosynthesis of Metal Complexes نيم سال اول

47 What is the advantage and disadvantage of this cryo method: Formation o very low temperature stable compound Rigidity of matrix Hard and expensive technique 47 SYNTHESIS AND CHARAC CTERIZAT TION OF INORGANIC COMP PLEXES

48 Note: There is a difference between this metalvapor/cryosynthesis method and other types of "direct synthesis" [27] (i.e. oxidative dissolution of bulk metals, electro- and mechanosynthesis). Thus, in this case, the bulk metal must be vaporized before its reaction with gaseous or frozen (in)organic ligand. This step is necessary to provide the absence for the metal of the kinetic or thermodynamic barriers that exist for the bulk metals, and this is precisely the reason for the success of cryosynthesis. SYNTHESIS AND CHARAC CTERIZAT TION OF 48 INORGANIC COMP PLEXES

1. Introduction. Introduction

1. Introduction. Introduction 1. The chemistry of organometallic compounds represents an important part of organic and pharmaceutical synthesis [1-6]. These compounds are used as catalysts in the stereospecific polymerization of olefins,