Interaction of quinones with dimeric manganese and rhenium carbonyls

It has been established that UV irradiation of manganese and rhenium dipentacarbonyls in the presence of o-quinones leads successively to the formation of primary phenoxyl-type radicals and to secondary complexes having a chelate structure. Ultraviolet irradiation of rhenium dipentacarbonyl in the presence of 3,6-di-t-butyl-2-hydroxy-1,4-benzoquinone leads to the formation of 3,6-di-t-butyl-5-Re(CO)₅-2-hydroxyphenoxyl which exists in two forms which differ in the location of the rhenium-containing fragment relative to the monovalent oxygen atom.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 161–168, January, 1990.     

Diphenyldichalcogenide complexes of iron, chromium and rhenium carbonyls

The substitution of a labile THF ligand in Cr(CO)₅(THF) by the Ph₂Se₂ molecule provided the monomeric complex Cr(CO)₅(Ph₂Se₂) (I). The similar diiodo-tricarbonyl-iron complex (CO)₃FeI₂(Ph₂Se₂) (II) (along with [(CO)₃Fe(??-SePh)₃Fe(CO)₃]⁺(I₅)^? (III) as a by-product) was separated upon the treatment of ??phenylselenyl iodide?? [PhSeI] with iron pentacarbonyl, Fe(CO)₅. Complex II is isostructural with the known tellurium-containing analogue, (CO)₃FeI₂(Te₂Ph₂). The latter have provided the dimeric tellurophenyl bridged iodo-tricarbonyl-iron complex [(CO)₃IFe(??-TePh)]₂ (IV) under action of the excess of Fe(CO)₅. Its bromide analogue [(CO)₃BrFe(??-TePh)]₂ (V) was prepared upon the treatment of PhTeBr with the excess of Fe(CO)₅. The reaction of [PhSeI] with Re(CO)₅Cl afforded only [(CO)₆Re₂(??-I)₂(??-Se₂Ph₂)] (VI) in contrast to the (CO)₃Re(PhTeI)₃(??₃-I) formation in similar known reaction of [PhTeI]. The molecular and crystal structures of I?CVI is discussed.     

Synthesis and reactivity of germyl complexes of manganese and rhenium

Trichlorogermyl complexes M(GeCl₃)(CO)_nP_{5− n} (1–4) [M = Mn, Re; n = 2, 3; P = PPh(OEt)₂ (a), P(OEt)₃ (b)] were prepared by allowing chloro compounds MCl(CO)_nP_{5− n} to react with an excess of GeCl₂•dioxane in 1,2-dichloroethane. Treatment of compounds 1–4 with LiAlH₄ in thf yielded trihydridegermyl derivatives M(GeH₃)(CO)_nP_5−n (5–8), whereas treatment of the same complexes with NaBH₄ in ethanol afforded triethoxygermyl derivatives M[Ge(OEt)₃](CO)_nP_5−n (9–11). Trimethylgermyl compounds M(GeMe₃)(CO)_nP_5−n (12, 13) and the alkynylgermyl derivative Mn[Ge(CCPh)₃](CO)₃[PPh(OEt)₂]₂ (14a) were also prepared by allowing trichlorogermyl compounds 1–4 to react with either MgBrMe or Li⁺CCPh⁻, respectively, in thf. Treatment of compound Re(GeCl₃)(CO)₃[PPh(OEt)₂]₂ (4a) with SnCl₂•2H₂O gave the stannyl-germyl derivative Re[GeCl₂(SnCl₃)](CO)₃[PPh(OEt)₂]₂ (15a). The complexes were characterised by spectroscopy and X-ray crystal structure determination of 4a, 5a, and 13a.     

Synthesis and reactivity of germyl complexes of manganese and rhenium

Trichlorogermyl complexes M(GeCl₃)(CO)_nP_{5? n} (1–4) [M = Mn, Re; n = 2, 3; P = PPh(OEt)₂ (a), P(OEt)₃ (b)] were prepared by allowing chloro compounds MCl(CO)_nP_{5? n} to react with an excess of GeCl₂?dioxane in 1,2-dichloroethane. Treatment of compounds 1–4 with LiAlH₄ in thf yielded trihydridegermyl derivatives M(GeH₃)(CO)_nP_5?n (5–8), whereas treatment of the same complexes with NaBH₄ in ethanol afforded triethoxygermyl derivatives M[Ge(OEt)₃](CO)_nP_5?n (9–11). Trimethylgermyl compounds M(GeMe₃)(CO)_nP_5?n (12, 13) and the alkynylgermyl derivative Mn[Ge(CCPh)₃](CO)₃[PPh(OEt)₂]₂ (14a) were also prepared by allowing trichlorogermyl compounds 1–4 to react with either MgBrMe or Li⁺CCPh^?, respectively, in thf. Treatment of compound Re(GeCl₃)(CO)₃[PPh(OEt)₂]₂ (4a) with SnCl₂?2H₂O gave the stannyl-germyl derivative Re[GeCl₂(SnCl₃)](CO)₃[PPh(OEt)₂]₂ (15a). The complexes were characterised by spectroscopy and X-ray crystal structure determination of 4a, 5a, and 13a.     

Preparation and protonation reactions of aryl complexes of manganese and rhenium

Aryl M(κ¹-Ar)(CO)_nP_5−n [M = Mn, Re; Ar = C₆H₅, 4-CH₃C₆H₄; n = 2, 3; P = P(OEt)₃, PPh(OEt)₂, PPh₂OEt] and Re(κ¹-C₆H₅)(CO)₃[Ph₂PO(CH₂)₃OPPh₂] complexes were prepared by allowing hydrides MH(CO)_nP_5−n to react first with triflic acid and then with the appropriate aryl lithium (LiAr) compounds. The complexes were characterized spectroscopically (IR and ¹H, ³¹P, ¹³C NMR) and by the X-ray crystal structure determination of Re(κ¹-C₆H₅)(CO)₃[Ph₂PO(CH₂)₃OPPh₂] derivative. Protonation reaction of the aryl complexes with HBF₄ · Et₂O lead to free hydrocarbons Ar-H and the unsaturated [M(CO)_nP_5−n]⁺ cations, separated as solids in the case of [Re(CO)₃P₂]BF₄ derivatives.     

Carbonyl complexes of manganese, rhenium and molybdenum with ethynyliminopyridine ligands

[MBr(CO)₅] reacts with m-ethynylphenylamine and pyridine-2-carboxaldehyde in refluxing tetrahydrofuran to give, fac-[MBr(CO)₃(py-2-CHN-C₆H₄-m-(CCH))] (M = Mn, 1a; Re, 2a). The same method affords the tetracarbonyl [Mo(CO)₄{py-2-CHN-C₆H₄-m-(CCH)}] (3a) starting from [Mo(CO)₄(piperidine)₂]; and the methallyl complex [MoCl(η³-C₃H₄Me-2)(CO)₂{py-2-CHN-C₆H₄-m-(CCH)}] (4a) from [MoCl(η³-C₃H₄Me-2)(CO)₂(NCMe)₂]. The use of p-ethynylphenylamine gives the corresponding derivatives (1b, 2b, 3b, and 4b) with the ethynyl substituent in the para-position at the phenyl ring of the iminopyridine. All complexes have been isolated as crystalline solids and characterized by analytical and spectroscopic methods. X-ray determinations, carried out on crystals of 1a, 1b, 2a, 2b, 3b, 4a, and 4b, reveals the same structural type for all compounds with small variations due mainly to the different size of the metal atoms. The reaction of complexes 1a or 2a with dicobalt octacarbonyl affords the tetrahedrane complexes [MBr(CO)₃{py-2-CHN-C₆H₄-m-{(μ-CCH)Co₂(CO)₆}}] (M = Mn, 5; Re, 6), the structures of which have been confirmed by an X-ray determination on a crystal of compound 5.     

Reaction of oxygen-containing monomers with triethylsilane in the presence of iron,manganese, and rhenium carbonyls

A study was carried out on the reaction of triethylsilane (TES) with acrolein, the diethyl acetal of acrolein, and allyl alcohol in the presence of Fe(CO)₅ Mn₂ (CO) ₁₀,and Re ₂ (CO) ₁₀.Acrolein reacts with TES in the presence of Fe(CO)₅ to give the 1,4-addition product in high yield. The reaction of the diethyl acetal of acrolein largely features cleavage of the C- O bond and formation of Et₃SiOEt.Allyl alcohol reacts with TES in the presence of Fe(CO)₅, Mn₂ (CO) ₁₀,and Re₂ (CO) ₁₀ to give the dehydrocondensation product, namely, triethylallyloxysilane, which undergoes hydrogenation and hydroxylation to give triethylpropyloxysilane and -(triethylsilyloxy)propyltriethylsilane, respectively. The yields of these products depend on the metal carbonyl used.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 483–485, February, 1990.     

Mesomorphic complexes of rhenium(I) and manganese(I)

Abstract

Following our discovery of liquid crystals based on octahedral manganese(I), we have now extended these studies to the synthesis of what we believe to be unique examples of mesomorphic rhenium-based complexes. These complexes offer advantages over the related manganese(I) systems in that they are more thermally stable. Further, modification of the organic backbone has led to lower melting manganese materials.     

Syntheses and structures of missing links among polybromocyclopentadienyl rhenium and manganese tricarbonyl complexes

Reactions of diazocyclopentadiene and NBS at appropriate stoichiometries give 2,5-dibromodiazocyclopentadiene and 2,3,5-tribromodiazocyclopentadiene in 40% and 30% yields, respectively, after chromatography. These react with BrRe(CO)₅ or BrMn(CO)₅ (80 °C, CF₃C₆H₅) to give (η⁵-1,2,3-C₅H₂Br₃)M(CO)₃ (3; M = a, Re; b, Mn) and (η⁵-C₅HBr₄)M(CO)₃ (4a,b) in 75-85% yields. In the case of 4a, the intermediate η¹-cyclopentadienyl complex (η¹-C₅HBr₄)Re(CO)₅ (4′a) can be isolated (44%). An isomer of 3b, (η⁵-1,2,4-C₅H₂Br₃)Mn(CO)₃, is accessed by desilylating previously reported (η⁵-1,2,4-C₅(SiMe₃)₂Br₃)Mn(CO)₃ with CsF/MeOH (85%). The reaction of tetrabromodiazocyclopentadiene and BrRe(CO)₅ at 80 °C in CF₃C₆H₅ gives the η¹-cyclopentadienyl complex (η¹-C₅Br₅)Re(CO)₅ (5′a, 74%) which cannot be induced to decarbonylate to (η⁵-C₅Br₅)Re(CO)₃ (5a) under a variety of conditions. However, 5a can be isolated (45%) when a similar reaction is conducted at 120 °C. The IR properties of the preceding complexes are compared, and the crystal structures of 3a, 3b, 5a, and 5′a are determined and analyzed.     

Carbonyl complexes of manganese, rhenium and molybdenum with 2-pyridylimino acid ligands

[MBr(CO)₃{κ²(N,O)-pyca}] [M = Mn(1a), Re(1b), pyca = pyridine-2-carboxaldehyde] and [MoCl(η³-C₃H₄Me-2)(CO)₂{κ²(N,O)-pyca}] (1c) react with aminoacid β-alanine to give the corresponding iminopyridine complexes 2a-2c. The same method affords the iminopyridine derivatives from γ-aminobutyric acid (GABA) (3a-3c) and 3-aminobenzoic acid (4a-4c). For complexes 2a-2c, 3a, 3c and 4a, the solid state structures have been determined by X-ray crystallography, revealing interesting differences in their hydrogen-bonding patterns in solid state.     

Reaction of mercury halides of cyclopentadienyl derivatives of manganese and rhenium carbonyls with triphenylphosphine complex of platinum(0)

Conclusions It was discovered that the mercury halides of the cyclopentadienyl derivatives of manganese and rhenium carbonyls react with tris(triphenylphosphine)platinum to give new complexes with a platnium-carbon -bond.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1894–1896, August, 1977.     

Reactions of manganese and rhenium complexes with organic azides: preparation of tetraazabutadiene derivatives

Azide complexes [M(RN(3))(CO)(3)P(2)]BPh(4)[M = Mn, Re; R = C(6)H(5)CH(2), 4-CH(3)C(6)H(4)CH(2), C(6)H(5), 4-CH(3)C(6)H(4), C(5)H(9); P = PPh(OEt)(2), PPh(2)(OEt)] were prepared by allowing tricarbonyl MH(CO)(3)P(2) hydride complexes to react first with Br?nsted acid (HBF(4), CF(3)SO(3)H) and then with organic azide in the dark. In sunlight the reaction yielded tetraazabutadiene [M(eta(2)-1,4-R(2)N(4))(CO)(2)P(2)]BPh(4) complexes or, with benzyl azide, imine [M{eta(1)-NH[double bond, length as m-dash]C(H)Ar}(CO)(3)P(2)]BPh(4)(Ar = C(6)H(5), 4-CH(3)C(6)H(4)) derivatives. Tetraazabutadiene [M(eta(2)-1,4-R(2)N(4))(CO)(2)P(2)]BPh(4) complexes were also prepared by reacting dicarbonyl MH(CO)(2)P(3) species first with Br?nsted acid and then with an excess of organic azide. Complexes were characterised spectroscopically (IR, (1)H, (31)P, (13)C, (15)N NMR data) and by the X-ray crystal structure determination of complex [Re{eta(2)-1,4-(C(6)H(5)CH(2))(2)N(4)}(CO)(2){PPh(OEt)(2)}(2)]BPh(4)(). Strong evidence for coordination of the organic azide was obtained from the (15)N NMR spectra of labelled [M(C(6)H(5)CH(2)(15)NN(15)N)(CO)(3)P(2)]BPh(4) derivatives.     

Atomic inversion barriers of sulphur and selenium in the dimethylsulphide and dimethylselenide complexes of the halogeno carbonyls of rhenium

We have synthesised four rhenium carbonyl complexes of general formula [ReX(CO)₃(Me₂E)₂] (X  Cl, Br, I, E  S, Se), and studied their temperature variable NMR spectra. All complexes were formed as the fac isomer, with the exception of [ReI(CO)₃(Me₂Se)₂], which was obtained as a mixture of mer and fac forms. In all of these fac complexes pyramidal inversion of sulphur or selenium atoms has been demonstrated, and energy barriers to inversion have been determined either by computer simulation of complete line shapes or by coalescence temperature methods. The value of ΔG^≠ for inversion in this class of complex has been found to be about 17 kJ mol^?1 higher for selenium than for sulphur, and variation of the cis halogen made no pronounced effect.     

Reactions of diazoles with manganese and iron carbonyls

The compounds of two types were isolated in the reactions of dimanganese decacarbonyl with diazoles. The compounds with an unaltered oxidation state of the metal were formed as a result of nucleophilic substitution of a carbonyl ligand of Mn₂(CO)₁₀. The compounds with an altered oxidation state of the central atom were produced in redox-transformations of Mn₂(CO)₁₀. The substances were characterized by the data of mass-, IR-, ¹H-NMR-spectra. The EPR-data were obtained for paramagnetic Mn²⁺ salts. The reactions of Mn₂(CO)₁₀ with diazoles are compared with those of iron carbonyls.