Reaction Of Thiocyanate Research Articles

Thermal Decomposition Reactions as Tool for the Synthesis of New Metal Thiocyanate Diazine Coordination Polymers with Cooperative Magnetic Phenomena

Reaction of nickel thiocyanate with pyrimidine at room temperature leads to the formation of the new ligand-rich 1:2 (1:2 = ratio between metal and ligand) compound [Ni(NCS)(2)(pyrimidine)(2)](n) (2) which is isotypic to [Co(NCS)(2)(pyrimidine)(2)](n) (1) reported recently. In the crystal structure, the Ni(2+) ions are coordinated by four N atoms of pyrimidine ligands, which connect the metal centers into layers, and two N atoms of terminal bonded thiocyanato anions within slightly distorted octahedra. If the synthesis is performed under solvothermal conditions and an excess of the metal thiocyanate is used, single crystals of the ligand-deficient 1:1 compound [Ni(NCS)(2)(pyrimidine)](n) (4) are obtained. Investigations on the synthesis of this compound show that it is always contaminated with large amounts of the corresponding ligand-rich 1:2 compound 2. In the crystal structure, the Ni(2+) ions are coordinated by two N atoms of pyrimidine ligands, which connect the metal centers into chains, and two N atoms as well as two S atoms of mu-1,3 bridged thiocyanato anions, which conntect these chains into layers, within a slightly distorted octahedral geometry. On heating compounds 1 and 2 transform quantitatively into the ligand-deficient 1:1 Ni compound 4 and its isotypic Co compound 3. If nickel and cobalt thiocyanate are reacted with an excess of pyrimidine in a solvent-free reaction, discrete ligand-rich 1:4 complexes of composition [M(NCS)(2)(pyrimidine)(4)] (M = Co 5 and Ni 6) are obtained, which could be determined by single crystal structure analysis. In their crystal structure the metal ions are coordinated by four terminal bonded pyrimidine ligands and two terminal N-bonded thiocyanato anions. For the ligand-rich 1:2 and ligand-deficient 1:1 compounds magnetic measurements were performed, which reveal different magnetic properties: The 1:2 compounds show a ferromagnetic and the 1:1 compounds an antiferromagnetic ordering at lower temperatures.

Synthesis, Crystal Structure, and Thermal and Magnetic Properties of New Transition Metal–Pyrazine Coordination Polymers

AbstractThe reaction of nickel thiocyanate with pyrazine in a 1:2 ratio leads to the new ligand‐rich 1:2 (ratio metal/ligand) compound [Ni(SCN)2(pyrazine)2]n (1), in which the metal atoms are coordinated by four N atoms of pyrazine ligands and two N atoms of thiocyanate anions in a slightly distorted octahedral arrangement. If an excess of the metal thiocyanate is used and the reaction is performed under solvothermal conditions, single crystals of the ligand‐deficient 1:1 compounds [M(SCN)2(pyrazine)2]n [M = Fe (2I), Co (3), Ni (4)] are obtained. Compound 2I is isotypic with [Mn(SCN)2(pyrazine)]n but different to 3 and 4, which are also isotypic. Investigations on the synthesis of these compounds reveal that only compound 4 can be prepared phase‐pure in solution; all other ligand‐deficient compounds are always contaminated with large amounts of the corresponding ligand‐rich coordination polymers. In the crystal structures, the metal atoms are surrounded by two N atoms of the pyrazine ligands as well as by two N atoms and two S atoms of the thiocyanate anions in a slightly distorted octahedral geometry. In contrast to the ligand‐rich 1:2 coordination polymers, the metal atoms are further linked into layers by the thiocyanate anions due to μ2‐N,S coordination. On heating, compound 1 and the ligand‐rich 1:2 coordination polymers [M(SCN)2(pyrazine)2]n (M = Fe, Co) transform quantitatively into the ligand‐deficient compounds. Surprisingly, thermal decomposition of the iron compound leads to a new modification (2II), which is isotypic to compounds 3 and 4. The magnetic properties of all compounds have been investigated and are found to be dependent on the connection mode of the thiocyanate anions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Formation of an oxathiolone compound from rutin in acidic mixture of saliva and buckwheat dough: Possibility of its occurrence in the stomach

Abstract Buckwheat is used for various foods in the world. The objective of the present study is the determination of the chemical structure of a product formed in the acidic mixture of buckwheat dough and saliva that contains both nitrite and thiocyanate. In the mixture, an oxathiolone derivative of rutin, 5,7-dihydroxy-2-(7-hydroxy-2-oxobenzo[d][1,3]oxathiol-4-yl)-4H-chromen-4-one-3-O-β-rutinoside, was found. This compound seemed to be formed by the hydrolysis of a 2′-thiocyanate derivative of rutin, which was produced by the reaction of thiocyanate with the o-quinone generated by nitrous acid-dependent oxidation of rutin. Importance of the formation of the oxathiolone compound is discussed in relation to scavenging of the toxic quinone in the stomach.

A new synthesis of alkane and polyfluoroalkanesulfonyl chlorides

AbstractThis study describes a new and advantageous procedure for the synthesis of alkanesulfonyl chlorides (2) by the reaction of alkyl thiocyanates (1) with sulfuryl chloride in a mixture of acetic acid and water. The alkanesulfonyl chlorides were obtained in good yields. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:355–361, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20559

N-Methylimidazole-promoted efficient synthesis of 1,3-oxazine-4-thiones under solvent-free conditions

A novel method for oxazine ring formation is established using the reaction of ammonium thiocyanate and acid chlorides with napthols in the presence of N-methylimidazole to afford [1,3]oxazine-4-thione derivatives in excellent yields.

How to prevent immunological reactions in leprosy patients and interrupt transmission of Mycobacterium leprae to healthy subjects: Two hypotheses

The basis of World Health Organization strategy for leprosy elimination is that the only source and reservoir for infection are patients with the disease. It was assumed that multi drug therapy (MDT) would reduce transmission of Mycobacterium leprae, but there is no convincing evidence for this. Furthermore, even if MDT has been proved to be extremely effective against the infectious disease, a noticeable proportion of leprosy patients can suffer from immunologic hypersensitivity reactions which are now the most significant issue in the managements of the disease. In endemic areas it was found that: M. leprae survives outside human body; healthy individuals harbor M. leprae bacilli in nasal cavity and shed micro-organisms in environment; there is widespread subclinical transmission of M. leprae with transient infection of the nose resulting in the development of a mucosal immune response. This disparate clinical, epidemiologic, and microbiologic evidence leads to the first hypothesis: that antigenic load in local tissues, sufficient to trigger the immune response, comes from external supply of M. leprae organisms. The hypothiocyanite anion (OSCN-) is generated in vivo by the reaction of thiocyanate with hydrogen peroxide catalyzed by lactoperoxidase. OSCN- is an antimicrobial oxidizing agent that prevents growth of bacteria, fungi, and viruses. OSNC- exists in lower airway secretions and lung has never been reported to be affected by leprosy. There is a sufficient concentration of OSCN- in the saliva, and accordingly mouth is rarely affected by leprosy. By contrast, the concentration of this compound is low or nil in nasal and lacrimal secretions and leprosy very often affects nose and eyes. The second hypothesis is that OSCN- may also protect from leprosy. Recently a method of OSCN- production, not involving enzymatic steps or use of toxic heavy-metal salts, has been patented. Studies on the susceptibility of M. leprae to hypothiocyanite could be carried out and, in case of positive results, the substance might be used in order to sterilize the nasal cavity of healthy carriers and prevent transmission of M. leprae to healthy subjects and to leprosy patients in whom it may trigger an immune response.

Synthesis, structure, and thermal decomposition of [H2(4,4′-Bipy)][In(H2O)2(NCS)4]2 and [HUr]2[In(H2O)(NCS)5] · 2H2O

The reaction of indium thiocyanate with bipyridine (4,4-Bipy) and urotropine (Ur) gave [H2(4,4′-Bipy)][In(H2O)2(NCS)4]2 (I) and [HUr]2[In(H2O)(NCS)5] · 2H2O (II), which were identified using elemental analysis, IR spectra, and thermogravimetric analysis. The thermal decomposition of compound I and II ends at 650 and 640°C, respectively, and gives In2O3. X-Ray diffraction analysis of compound I showed that complex anions in the crystal form chains through O-H…S hydrogen bonds. The anion chains form a close packing of columns with bipyridine cations located in the voids.

Acid-catalyzed reactions of thiocyanates with camphene

The reactions of thiocyanates with camphene catalyzed by the heteropoly acids H3PW12O40 and H4SiW12O40 were studied. The optimal reaction conditions were found, and the formation of N-substituted thiocarbamates in comparatively high yields was established. It was shown that the heteropoly acids exhibit a higher catalytic activity than sulfuric acid.

ChemInform Abstract: Four‐Component One‐Pot Synthesis of Functionalized Ynamines from Reaction of Benzoyl Chlorides, Secondary Amines, Acetylenic Esters and Ammonium Thiocyanate.

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Synthesis of 2‐(5‐Substituted‐1,3,4‐thiadiazolo‐2‐ylimino)‐4‐thiazolidinones under Microwave Irradiation

Fifteen 2‐(5‐substituted‐1,3,4‐thiadiazolo‐2‐ylimino)‐4‐thiazolidinones were efficiently synthesized from the reaction of ammonium thiocyanate with 2‐chloro‐N‐(5‐substutited‐1,3,4‐thiadiazolo‐2‐yl)acetamides under microwave irradiation. The target compounds were obtained in better yields (75–98%) and shorter time (5 min) than with conventional heating.

Structural, magnetic, high-frequency and high-field EPR investigation of double-stranded heterometallic [{Ni(en)2}2(µ-NCS)4Cd(NCS)2]n·nCH3CN polymer self-assembled from cadmium oxide, nickel thiocyanate and ethylenediamine

A novel heterometallic 1D coordination polymer [{Ni(en)2}2(micro-NCS)4Cd(NCS)2](n) x nCH3CN (en = ethylenediamine) has been prepared using the self-assembly process in a one-pot reaction of cadmium oxide, nickel and ammonium thiocyanates with an acetonitrile solution of ethylenediamine. The complex consists of an uncommon cis-Cd(SCN)4(NCS)2(4-) fragment and a rare combination of cis-Ni(en)2(2+) and trans-Ni(en)2(2+) building blocks linked by micro(1,3)-NCS bridges into a double-stranded zigzag chain structure. Each chain is comprised of [Ni2Cd2(micro-NCS-N,S)4)] macrocycles with chair-like and rectangular-like shapes arrayed alternately. The shortest intrachain CdCd separations are 9.535(1) and 10.868(2) A, while the nearest NiNi distances are 5.418(1) and 6.612(2) A. A network of weak N-HS hydrogen bonds, involving the terminal NCS ligands and NH2-groups of en, links the infinite chains and results in the formation of an extended supramolecular three-dimensional framework. Variable-temperature (1.8-300 K) magnetic susceptibilities show a slight change of the micro(B) value at low temperature, indicative of weak antiferromagnetic interactions (J = 1.55 cm-1) between magnetic canters. High-field, high-frequency (100-400 GHz) EPR spectra were simulated using S = 1 ground state for separate Ni2+ ions with the spin Hamiltonian parameters g = 2.165, D = 0.45 cm-1 and E = 0.03 cm(-1). According to DFT calculations, the D and E parameters are -0.35 cm(-1) and 0.049 cm-1 for the cis arrangement of Ni2+ and 0.58 cm(-1) and 0.012 cm(-1) for trans.

Synthesis of S-glycosyl thiophosphates, thiophosphonates and thiophosphinates by the Michaelis–Arbuzov rearrangement of anomeric thiocyanates

Reaction of anomeric thiocyanates with a series of O-alkyl or O-trimethylsilyl phosphite, phenylphosphonite and diphenylphosphinite derivatives afforded the corresponding S-glycosyl thiophosphates, thiophosphonates and thiophosphinates in good yields. These derivatives had been previously applied as glycosyl donors in the synthesis of benzyl glycosides and disaccharides with excellent stereoselectivity.

Four-Component One-Pot Synthesis of Functionalized Ynamines from Reaction of Benzoyl Chlorides, Secondary Amines, Acetylenic Esters and Ammonium Thiocyanate

An efficient one-pot synthesis of functionalized ynamines is described. This involves the four-component reaction of ammonium thiocyanate, benzoyl chlorides, and secondary c amines in the presence of dialkyl acetylenedicarboxylates.

The Michaelis–Arbuzov rearrangement of anomeric thiocyanates: synthesis and application of S-glycosyl thiophosphates, thiophosphonates and thiophosphinates as glycosyl donors

Reaction of anomeric thiocyanates with triethyl phosphite, dimethyl phenylphosphonite and methyl diphenylphosphinite afforded the corresponding S-glycosyl thiophosphates, thiophosphonates and thiophosphinates in good yields. These derivatives were applied as glycosyl donors in the synthesis of benzyl glycosides and disaccharides with excellent stereoselectivity.

Reactions of cysteine sulfenyl thiocyanate with thiols to give unsymmetrical disulfides

AbstractCysteine sulfenyl thiocyanate (CSSCN) reacts with thiols at pH 0 to cleanly yield disulfides. 2‐Mercaptoethanol (2‐MESH), 3‐mercaptopropionic acid (3‐MPASH), penicillamine (PENSH), and glutathione (GSH) react with CSSCN to give the corresponding mixed disulfides: 2‐MESSC, 3‐MPASSC, PENSSC, and GSSC. These compounds are stable at pH 0 and have been characterized by 1H and 13C NMR spectroscopy. © 2007 Wiley Periodicals, Inc. 18:467–471, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20340

A new stereoselective synthesis of 2-amino-4,5-dihydrothiophene-3-carbonitrile derivatives

A new stereoselective method for the synthesis of trans-isomers of 2-amino-4-aryl-5-benzoyl-4,5-dihydrothiophene-3-carbonitriles was proposed. The method involves base-catalyzed reactions of phenacyl thiocyanate with 3-(het)aryl-2-cyanoprop-2-enethioamides. (4R,5S/4S,5R)-2-Amino-5-benzoyl-4-(2-chlorophenyl)-4,5-ihydrothiophene-3-carbonitrile was structurally characterized by X-ray diffraction analysis.

Synthesis of a new thiocarbamate by the reaction of benzyl thiocyanate with camphene, catalyzed by heteropoly acids

The reaction of benzyl thiocyanate with camphene in the presence of heteropoly acids, 12-phosphotungstic and 12-silicotungstic, at 65 C was studied. S-Benzyl (1,7,7-trimethylnorbornyl)thiocarbamate was prepared in 66% yield.

Reactions of thiocyanate in the mixture of nitrite and hydrogen peroxide under acidic conditions: Investigation of the reactions simulating the mixture of saliva and gastric juice

Nitrite and SCN− in saliva can mixes with H2O2 in the stomach. The mixing can result in the formation of ONOOH. It is not yet known how salivary SCN− reacts with ONOOH. An objective of the present study was to elucidate the reaction between ONOOH and SCN− . In nitrite/H2O2 systems at pH 2, SCN− inhibited the consumption of nitrite and the formation of . SCN− enhanced the decomposition of ONOOH and H2O2 in HNO2/H2O2 systems. Accompanying the reactions, sulfate was formed, suggesting that ONOOH oxidized SCN− . SCN− inhibited the nitration of phenolics induced by HNO2/H2O2. The inhibition is discussed taking SCN− -dependent reduction of ONOOH to HNO2 into consideration. SCN− also inhibited H2O2-induced consumption of nitrite and nitration of phenolics in acidified saliva. The result obtained in this study suggests that salivary SCN− can reduce ONOOH to /HNO2 inhibiting nitrating reactions in the stomach.

Thiocyanate Functionalised Ionic Liquids: Synthesis, Characterisation and Reactivity

AbstractThe reaction of chloromethyl thiocyanate with 1‐methylimidazole affords the imidazolium salt, 1‐thiocyanomethyl‐3‐methylimidazolium chloride, [C1SCNmim]Cl (1a). Exchange of the chloride anion in 1a by [PF6]–, [BF4]–, [Tf2N]– or [AuCl4]– affords salts 1b, 1c, 1d and 1e, respectively. Salts [C1SCNmim][BF4] (1c) and [C1SCNmim][Tf2N] (1d) melt below 100 °C and can therefore be classified as ionic liquids. The reaction of 1a with PdCl2 affords [C1SCNmim]2[PdCl4] (2a), whereas 1c reacts with PdCl2 to form the complex [PdCl2{C1SCNmim}2][BF4]2 (2c). In the presence of HNO3 both 1a and 1c react with PdCl2 with the loss of HCN to form a sulfide‐bridged palladium dimer [PdCl2{C1Smim}]2 (3). The structures of 1a, 1e, 2a and 3 have been determined in the solid state by single‐crystal X‐ray diffraction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

A New Synthetic Route to Polyalkoxypyrimidines Based on the Reaction of Esters and Methyl Thiocyanate.

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