Fedor M. Dolgushin

Reactions of diacetylene ligands with trinuclear clusters. I Reactions of 2,4-hexadiyne-1,6-diol and its dicobalthexacarbonyl derivatives with H2Os3(CO)10

Abstract Reactions of H 2 Os 3 (CO) 10 with the diyne ligand HOCH 2 C 2 C 2 CH 2 OH and its dicobalthexacarbonyl derivatives {CO 2 (CO) 6 }(μ 2 ,η 2 -HOCH 2 C 2 C 2 CH 2 OH) and {Co 2 (CO) 6 } 2 (μ 2 ,η 2 : μ 2 ,η 2 -HOCH 2 C 2 C 2 CH 2 OH) have been studied. The reaction of the uncomplexed ligand yields the cluster with the completely rearranged starting ligand. The structure of this compound was determined by a single-crystal X-ray study. The rearranged ligand forms a pseudo-furan ring with the C CH 3 substituent in the α-position. The reactions of H 2 Os 3 (CO) 10 with the both dicobalthexacarbonyl derivatives yield the (μ-H)(μ-OH)Os 3 (CO) 10 cluster ar the main osmium-containing product. The structure of this compound was also established by a single-crystal X-ray study.

Coordination chemistry of polymercuramacrocycles. Complexation of cyclic trimeric perfluoro-o-phenylenemercury with neutral oxygeneous Lewis bases

Cyclic trimeric perfluoro- o -phenylenemercury ( o -C 6 F 4 Hg) 3 ( I ) readily reacts with N , N -dimethylformamide and hexamethylphosphoramide to form complexes {[( o -C 6 F 4 Hg) 3 ](HCONMe 2 ) 2 } ( II ) and {[( o -C 6 F 4 Hg) 3 ][(Me 2 N) 3 PO] 2 } ( III ), respectively, which contain two amide ligands per one macrocycle molecule. An X-ray diffraction study of II and III has shown that they have bipyramidal structures wherein the molecules of an amide are located above and below the metallacycle plane and each of them is simultaneously bonded via the oxygen atom to all Hg atoms of the cycle. The reaction of I with dimethylsulfoxide affords complex {[( o -C 6 F 4 Hg) 3 ](Me 2 SO) 3 } ( VI ) containing three Lewis basic species per molecule of I . According to X-ray diffraction data, two of three dimethylsulfoxide ligands in VI are also coordinated through the oxygen atom with all mercury centres of the macrocycle, forming a bipyramidal structure, while the third sulfoxide ligand is bonded only to one Hg atom of the cycle. The complex of similar composition and structure, {[( o -C 6 F 4 Hg) 3 ](MeCOOEt) 3 } ( IV ), is produced in the interaction of I with ethyl acetate but this complex is much less stable than VI . The latter correlates with a considerably lower Lewis basicity of ethyl acetate as compared to that of dimethylsulfoxide.

Carborane Complexes of Ruthenium(III): Studies on Thermal Reaction Chemistry and the Catalyst Design for Atom Transfer Radical Polymerization of Methyl Methacrylate

The heating of the 18-electron complex [3,3-(dppb)-3-H-3-Cl-closo-3,1,2-RuC(2)B(9)H(11)] (3) in benzene at 80 °C in the presence of a small amount of CCl(4) as initiator afforded paramagnetic 17-electron species [3,3-(dppb)-3-Cl-closo-3,1,2-RuC(2)B(9)H(11)] (4) along with minor amounts of two P-phenylene ortho-cycloboronated derivatives [3-Cl-3,3,8-{Ph(2)P(CH(2))(4)PPh-μ-(C(6)H(4)-ortho)}-closo-3,1,2-RuC(2)B(9)H(10)] (5) and [3,7-Cl(2)-3,3,8-{Ph(2)P(CH(2))(4)PPh-μ-(C(6)H(4)-ortho)}-closo-3,1,2-RuC(2)B(9)H(10)] (6) in total yield of ca. 80%. The heating of either 3 or 4 in toluene at 95 °C in the absence of CCl(4) led to the selective formation of 5, which was isolated in 64% and 46% yield, respectively. Thermolysis of 3 at higher temperatures (boiling toluene, 110 °C) gives novel paramagnetic species [3-Cl-3,3,7,8-{Ph(2)P(CH(2))(4)P-μ-(C(6)H(4)-ortho)(2)}-closo-3,1,2-RuC(2)B(9)H(9)] (7) featuring bis(ortho-cycloboronation) of both P-phenyl groups at the same phosphorus atom of the ruthenium-bound dppb ligand. All new paramagnetic complexes 4-7, as well as starting diamagnetic species 3, were characterized by single-crystal X-ray diffraction and, in addition, by EPR spectroscopic studies of odd-electron complexes. Ruthenacarboranes 3-5 and 7 all display high efficiency as catalysts for the atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA). Complex 5 gave the best catalyst performance in terms of polydispersity; the PDI (M(w)/M(n)) of the polymer samples is as low as 1.15.

Crown Compounds for Anions: Sandwich and Half-Sandwich Complexes of Cyclic Trimeric Perfluoro-o-phenylenemercury with Polyhedralcloso-[B10H10]2− andcloso-[B12H12]2− Anions

It has been shown by IR and NMR spectroscopy that cyclic trimeric perfluoro-o-phenylenemercury (o-C6F4-Hg)3 (1) is capable of binding closo-[B10H10]2- and closo-[B12H12]2- anions to form complexes [[(o-C6F4Hg)3](B10-H10)]2- (2), [[(o-C6F4Hg)3]2(B10H10)]2-(3), [[(o-C6F4Hg)3](B12H12)]2- (4), and [[(o-C6F4Hg)3]2(B12H12)]2- (5). According to IR data, the bonding of the [B10H10]2- and [B12H12]2- ions to the macrocycle in these complexes is accomplished through the formation of B-H-Hg bridges. Complexes 2, 3, and 5 have been isolated in analytically pure form and have been characterized by spectroscopic means. X-ray diffraction studies of 3 and 5 have revealed that these compounds have unusual sandwich structures, in which the polyhedral di-anion is located between the planes of two molecules of 1 and is bonded to each of them through two types of B-H-Hg bridges. One type is the simultaneous coordination of a B-H group to all three Hg atoms of the macrocycle. The other type is the coordination of a B-H group to a single Hg atom of the cycle. According to X-ray diffraction data, complex 2 has an analogous but half-sandwich structure. The obtained complexes 2-5 are quite stable; their stability constants in THF/acetone (1:1) at 20 degrees C have been determined as 1.0 x 10(2)Lmol(-1), 2.6 x 10(3)L(2)mol(2), 0.7 x 10(2)Lmol(-1), and 0.98 x 10(3)L(2)mol(-2), respectively.

Peculiarities of the Complexation of Copper and Silver Adducts of a 3, 5-Bis (trifluoromethyl) pyrazolate Ligand with Organoiron Compounds

Interaction of the copper, {[3,5-(CF(3))(2)Pz]Cu}(3), and silver, {[3,5-(CF(3))(2)Pz]Ag}(3), macrocycles [3,5-(CF(3))(2)Pz = 3,5-bis(trifluoromethyl)pyrazolate] with cyclooctatetraeneiron tricarbonyl, (cot)Fe(CO)(3), was investigated by IR and NMR spectroscopy for the first time. The formation of 1:1 complexes was observed at low temperatures in hexane. The composition of the complexes (1:1) and their thermodynamic characteristics in hexane and dichloromethane were determined. The π-electron system of (cot)Fe(CO)(3) was proven to be the sole site of coordination in solution and in the solid state. However, according to the single-crystal X-ray data, the complex has a different (2:1) composition featuring the sandwich structure. The complexes of ferrocene with copper and silver macrocycles have a columnar structure (X-ray data).

Crown compounds for anions. A spinning top-shaped complex of cyclic pentameric perfluoroisopropylidenemercury with two chloride anions

Abstract It has been found that cyclic pentameric perfluoroisopropylidenemercury, [(CF 3 ) 2 CHg] 5 , is capable of forming complexes with [PPh 4 ] + Cl − and [PPh 4 ] + Br − of the type {[(CF 3 ) 2 CHg] 5 X 2 } 2− [PPh 4 ] 2 + (X = Cl or Br). According to an X-ray diffraction study, the chloride anions in the complex of [(CF 3 ) 2 CHg] 5 with [PPh 4 ] + Cl − are located above and below the mercury-containing metallacycle, each Cl − anion being coordinated with all the five mercury atoms of [(CF 3 ) 2 CHg] 5 .

Complexation of cyclic trimeric perfluoro-o-phenylenemercury with nitriles. A remarkable sensitivity of the composition and structure of the resulting complexes to the nature of a nitrile

Abstract Cyclic trimeric perfluoro-o-phenylenemercury (o-C6F4Hg)3 (I) is capable of reacting with nitriles to form complexes whose composition and structure are dramatically dependent on the nature of the nitrile used. In the case of acrylonitrile, the complex, [(o-C6F4Hg)3(CH2CHCN)], containing one nitrile molecule per one molecule of I is produced. According to an X-ray structure analysis, the acrylonitrile ligand in this complex is bonded to all Hg atoms of the cycle through the nitrogen atom. The reaction of I with acetonitrile gives complex [(o-C6F4Hg)3(MeCN)2] which contains two nitrile ligand per one molecule of the macrocycle. This complex has a shape of a spinning top the equatorial girdle of which is the mercury-containing metallacycle, whilst the axis direction is fixed by the linear MeCN ligands located above and below the metallacycle plane. Finally, the isolated complex of I with benzonitrile, [(o-C6F4Hg)3(PhCN)3], contains three molecules of the coordinated nitrile per one macrocycle molecule. A remarkable structural feature of this complex is that here all the nitrile ligands are located on one side of the metallacycle plane and, in addition, differ from each other in the geometry of coordination with the Hg atoms.

Crown compounds for anions. A polymeric complex of cyclic trimeric perfluoro-o-phenylenemercury with thiocyanate anion containing an infinite helical chain of alternating molecules of mercury-containing macrocycle and SCN− ions

Abstract It has been shown by IR spectroscopy that cyclic trimeric perfluoro-o-phenylenemercury (o-C6F4Hg)3 is capable of binding thiocyanate anions in acetone solution, forming complexes whose composition is dependent on the ratio of reagents. In the interaction of (o-C6F4Hg)3 with an equimolar amount of [nBu4N]+ SCN− in ethanol the complex formulated as [(o- C 6 F 4 Hg ) 3 ( SCN )] − [ n Bu 4 N ] + has been isolated. An X-ray diffraction study of the complex has revealed that in the solid state it is polymeric and contains an infinite helical chain of alternating (o-C6F4Hg)3 molecules and thiocyanate anions. Every SCN− ion in the complex is bonded to the mercury atoms of two neighbouring molecules of the macrocycle through the sulphur atom and forms with each of these molecules two relatively short Hg … S bonds and one considerably longer Hg … S bond.

Synthesis, crystal and molecular structure of [{C5Me5FeC5Me4CH2}+B{C6H3(CF3)2}4−], the first example of a structurally characterized primary ferrocenylcarbocation

Abstract The synthesis and the first X-ray structural study of a salt of the primary ferrocenylcarbocation [{C5Me5MC5Me4CH2}+B{C6H3(CF3)2}4−] (M=Fe, 1a) are reported. The CCp–Cα bond shows considerable inclination relative to the plane of the cyclopentadienyl ring so that the Cα atom becomes closer to the metal centre, the inclination angle α being equal to 23.6°. The Fe–Cα distance (2.567(12) A) is still significantly longer than the covalent Fe–C σ-bond, which may be considered as an indication that the donor–acceptor interaction of the carbocationic centre with the metal electron pair is substantially weaker than in the earlier studied Ru- and Os-analogues (1b, 1c) wherein the positive charge was mostly localized on the metal centre (metallonium cations). Thus, complex 1a obviously preserves much more of the carbocationic state than its heavier analogues.

Metal-mediated coupling of a coordinated isocyanide and indazoles

A reaction between equimolar amounts of cis-[PdCl2(CNCy)2] (1) and indazole (HInd, 2) or 5-methylindazole (HInd(Me), 3) proceeded in refluxing CHCl3 for ca. 6 h affording the aminocarbene species cis-[PdCl2{C(Ind)=N(H)Cy}(CNCy)] (4) or cis-[PdCl2{C(Ind(Me))=N(H)Cy}(CNCy)] (5) in good (72-83%) isolated yields. Complexes 4 and 5 were characterized by elemental analyses (C, H, N), HR ESI(+)-MS, IR, and 1D ((1)H, (13)C{(1)H}) and 2D ((1)H,(1)H-COSY, (1)H,(13)C-HMQC/(1)H,(13)C-HSQC, (1)H,(13)C-HMBC) NMR spectroscopies, and complex 4 as well by X-ray diffraction. The observed coupling represents the first example of metal-mediated integration between any isocyanide and any aromatic heterocyclic system having an HN center.