Synthesis and structural elucidation of some new heterocyclic β-diketone derivatives of boron

Some new β-diketone derivatives of boron having the general formula B₂O(OAc)_4?n[OC(R)$\text{C:CON(Ph)N:C}$ CH₃]_n (where n = 1 or 2; R = CH₃, C₂H₅, C₆H₅ and p-ClC₆H₄) have been synthesised by the reactions of oxy-bis(diacetatoborane) and substituted pyrazolones, such as 4-acyl-3-methyl-1-phenyl-2-pyrazolin-5-ones (acyl = acetyl, propionyl, benzoyl and p-chlorobenzoyl) in dry toluene solution in 1:1 and 1:2 molar ratios. These derivatives have been characterised by elemental analysis, molecular weight measurements. Structures have been proposed on the basis of chemical reactions, IR, ¹H and ¹¹B NMR spectral studies.In the derivatives B₂O(OAc)₃[OC(R)$\text{C:CON(Ph)N:C}$ CH₃] two of the three acetate groups are unidentate and the third is bridged between two boron atoms along with BOB linkage. Whereas the derivatives B₂O(OAc)₂[OC(R)$\text{C:CON(Ph)N:C}$ CH₃]₂ are the mixture of geometrical isomers.     

Reaction of PF5·CH3CN with sulfide

Nitriles react with PF₅ and also with AsF₅, SbF₅ forming 1:1-adducts. Using C₂Cl₃F₃ as a solvent is of advantage for this reaction. PF₅·CH₃CN and [N(C₂H₅)₄]SH give [N(C₂H₅)₄][P₂S₂F₈] with a sulfur double bridge and hexafluorophosphate in acetonitrile [1]. In case of AsF₅·CH₃CN a salt with the anion [AsF₅NHCSCH₃]^? has been isolated [2]. Following products have been confirmed in a reaction mixture of PF₅·CH₃CN and SH^? in acetonitrile by NMR (³¹P and ¹⁹F): [PF₆]^?, [F₅PSPF₅]^2?,

, F₄PSH, F₃PS, HPS₂F₂, [PS₂F₂]^?, [F₅PNC(SH)CH₃]^?, [F₅PNHCSCH₃]^?, [F₅PSH]^?. With a ratio PF₅·CH₃CN: SH^? = 2:1 the S-bridge-complexes are prefered whereas in case of a ratio 1:1 the non-bridged P-complexes are the main products.     

Alkoxylierung von bis(trimethylsilyl)-aminofluorsilanen,sowie siloxanbildung unter äthereliminierung

The reaction of bis(trimethylsilyl)aminofluorsilanes, (Me₃Si)₂NSiF₂R (R = CH₃ or F), with sodium alcoholates or sodium phenylate yields under elimination of NaF alkoxy- and aryloxy-aminofluorosilanes of the composition (Me₃Si)₂NSiF(R)OR′(R′ = CH₃, C₂H₅, C₃H₇, C₆H₅). A disiloxane is formed by thermal elimination of diethyl ether from bis(trimethylsilyl)aminomethylfluoroethoxysilane. The IR, mass, ¹H and ¹⁹F NMR spectra of the above-mentioned compounds are reported. ab]Die Reaktion von Bis(trimethylsilyl)-aminofluorsilanen des Typs (Me₃Si)₂NSiF₂R (R = F, CH₃) mit Natriumalkoholaten und Natriumphenolat führt unter NaF-Abspaltung zu Alkyl- und Aryloxyaminofluorsilanen der Zusammensetzung: (Me₃Si)₂NSiF(R)OR′ (R′ = CH₃, C₂H₇, C₆H₅, C₆H₅). Ein Disiloxan könnte durch die thermische Eliminierung von Diäthyläther aus Bis(trimethylsilyl)aminomethyl-fluor-äthoxy-silylarnin erhalten werden.Die IR-, Massen-, ¹H- und ¹⁹F-NMR-Spektren der dargestellten Verbindungen werden mitgeteilt.     

Über die Umsetzung von P4E3I2 (E = S,Se) mit einigen Carbonsäuren und Dithiocarbonsäuren

On the Reaction of P₄E₃I₂ (E = S, Se) with some Carboxylic Acids and Dithiocarbamic Acids By the reaction of α-P₄E₃I₂ (E = S, Se) with carboxylic acids, dithiobenzoic acid or dithiocarbamic acids in the presence of triethylamin or with (C₆H₅)₃SnR, or of β-P₄E₃I₂ with tin-organic compounds α-P₄E₃(I)R, α(β)-P₄E₃R₂ [R = ? OC(O)C₆H₅, ? OC(O)CH₃, ? SC(S)NC₅H₁₀, ? SC(S)N(C₂H₅)₂], α-P₄S₃(I)SC(S)C₆H₅, α-P₄S₃(SC(S)C₆H₅)₂ and β-P₄E₃(I)R (R = ? OC(O)C₆H₅, ? OC(O)CH₃) were prepared in solution and identified by ³¹P NMR spectroscopy. In addition α-P₄S₃(NC₅H₁₀)(SC(S)NC₅H₁₀) was detected. The β-isomers could be obtained also with lesser yields by the reaction with the dithiocarbamic acids, too. The substitution of the second iodine ligand in β-P₄E₃I₂ resulted mainly in β-P₄S₃(R_exo)₂ and by inversion of the configuration at a phosphorus atom, in β-P₄E₃R_exoR_endo. α-P₄S₃I₂ reacted with methanol in CS₂ to α-P₄S₃(OCH₃)(SC(S)OCH₃) and α-P₄S₃(SC(S)OCH₃)₂. The ³¹P NMR data of the compounds are discussed. The ³¹P NMR spectra of the α(β)-P₄E₃ dithiocarbamates indicate dynamic processes in the solution, e. g. α-P₄S₃(I)(SC(S)NR₂) showed an intramolecular conversion, due to the anisobidentate dithiocarbamate ligand. This behaviour had not previously been noticed for compounds with a P₄S₃-skeleton.     

Fluorphosphorylamide

The preparation of some new phosphorus-fluoroamides of the type RP(O)FNH₂ is described (R = CH₃O-, C₆H₅O-, NH₂-, C₂H₅O-, CH₃NH-, C₂H₅NH-, C₆H₅-, C₆H₁₁-, C₂H₅-, CH₃-, and C₆H₅S-). All of the R? P(O)FNH₂ compounds were prepared at ?80°C in diethylether from the corresponding difluorides RP(O)F₂ and ammonia: RP(O)F₂ + 2NH₃ → RP(O)FNH₂ + NH₄F. When P(O)FCl₂ is reacted with ammonia in a molar ratio of 1:4, the hitherto unknown diamide of the series P(O)F_3?n(NH₂)_n (n = 1,2,3) is formed. As starting compounds, CH₃OP(O)F₂ and CH₃NHP(O)F₂ were obtained for the first time. The shifts of characteristic valency frequencies and some nmr data are discussed in homologous series.     

Pentafluorphenylverbindungen des Phosphors

Pentafluorophenyl Compounds of Phosphorus The preparation of compounds of the type R(C₆F₅)PX (R = CH₃, C₂H₅, t-C₄H₉ and C₆H₅: X = F, Cl, Br and N(C₂H₅)₂) is described. These derivatives are converted to trifluorophosphoranes, R(C₆F₅)PF₃, and phosphinic acid fluorides, R(C₆H₅)P(:O)F. The n.m.r. spectra are discussed.     

Organische Phosphorverbindungen XXXVIII. Darstellung und Eigenschaften von Tris-(dialkoxyphosphonyl-methyl)-, Tris-(alkoxyphosphinyl-methyl)-und Tris-(oxophosphoranyl-methyl)-phosphinsäureestern sowie der entsprechenden Säuren [1]

Tris-chloromethyl-phosphine oxide, (ClCH₂₎₃ P?O(I), is obtained by chlorination of (HOCH₂₎₃P?O with PCl₅ or (C₆H₅₎₃PCl₂, and also by oxidation of (CICH₂₎₃P?O and (ClCh₂₎₂(CH₃)P?O. High yields of tris-(dialkyloxyphosphonly-methyl)-phosphine oxides, [RO₂(O)PCH_2]2P?O (II) (R?CH₃, C₂H₅, iso-C₃H₇, n-C₄H₉, 2- ethyl-hexyl), tris (alkyloxyphosphinyl-methyl)-phosphine oxides, [R₂(O)PCH_2]3P?O(R = C₆H₅, CH₃) are obtained by heating tris-chloromethyl-phosphine oxides, [(RO) (R′) (O)PCH_2]3P?O (R = C₄H₉, R′? C₆H₅) and tris-(oxophosphoranyl-phosphine oxides with phosphites, phosphonites and phosphinites, respectively, at 170–180°C for several hours. Compounds II possess an extraordinarily high absorption capacity. Thus a warm. 2% solution of II (R = C₂H₅) in benzene solidifies completely on cooling so that no benzene can be poured off. Tris-dihydroxyphosphonyl-methyl)-phosphine oxide, [(HO)₂(O)PCH_2]3P?O, obtained by hydrolysis of II (R ? C₂H₅) with refluxing conc. HCl or by thermal decomposition of II (R ? iso-C₃H₇) at 190°, titrates in aqueous solution as a hexabasic acid with breaks at pH = 4,4 (three equivalents) and pH = 10,7 (three equivalents). It forms crystalline salts with amines, alkali and alkaline earth metals, and is an excellent chelating agent. The ¹H- and ^31?P-NMR. spectra of all the compounds prepared are discussed.     

Synthese von Fluoro-λ5-monophosphazenen und Fluoro-1, 3-diaza-2λ5, 4λ5-diphosphetidinen mittels der Staudinger-Reaktion

Synthesis of Fluoro-λ⁵-monophosphazenes and Fluoro-1,3-diaza-2λ⁵,4λ⁵-diphosphetidines by Means of the Staudinger Reaction 35 Tetrafluoro- and 2 difluorodiaza-diphosphetidines as well as 4 difluoro- and 30 monofluoro-λ⁵-monophosphazenes were prepared by the Staudinger reaction between tervalent phosphorus fluorides, R_nPF_3?n (n = 1, 2; R = R₂N, (CH₂)₅N, O(CH₂)₄N, RO, (CH₂O)₂, alkyl, aryl) and phenylazides, X? C₆H₄N₃ (X = H, 4-CH₃, 4-Cl, 4-Br, 4-NO₂, 3-NO₂). PF₃ does not react with phenylazide The influence of substituents on the structure of the reaction products is discussed. Kinetic measurements allowed to determine the constants λ^P_I of the substituents (CH₂)₅N, O(CH₂)₄N and R(C₆H₅)N (R = CH₃, C₂H₅, n-C₄H₉).     

Reactions of some fluoroaromatics with the ethoxide anion

The reactions of sodium ethoxide in ethanol with various fluoroaromatics, C₆F_6?nH_n, C₆F_5?nH_nNO₂, C₆F₅X (X = CF₃, C₆F₅, COCH₃, CH₂Br), C₆Cl₆ and $\text{m}$H₂C₆Cl₄ have been studied. Partial substitution of the aromatic halogen was observed. The new products have been characterized by elemental analysis, NMR (H?1 and F?19), infrared and mass spectroscopy.     

Substitution reactions of IF5

Using silyl protected organic hydroxo compounds substitution of fluorine in IF₅ is successful.Reacting IF₅ with Si(OCH₃)₄ in CH₃CN or SO₂ using different molar ratios it was shown that in the series IF_5?n(OCH₃)_n only the first member IF₄(OCH₃) (n=1) is stable enough to be isolated. The product in solution with n=2 bismutates to products with n=1 and n=3 if isolated as solids. The last one decomposes to the new oxo compound IF₂O(OCH₃) under elimination of CH₃OCH₃. With n=4,5 only redox reaction products could be isolated.IF₂O(OCH₃) can also be obtained by treating IF₄(OCH₃) with (CH₃)₆Si₂O. Similarly reaction of IF₅ with the disiloxane represents a new method to win IOF₃. Excess of the oxygen transfer reagent leads to formation of IO₂F and I₂O₅. An other oxo compound, IO(CH₃COO)₃, can be prepared by disolving IF₅, IOF₃ or IO₂F in acetic acid anhydride.Reactions of IF₅ with trimethylsilyl protected fluorinated benzoic acids R_fCOOSi(CH₃)₃ (R_f = C₆F₅, 4HC₆F₄) appeared to be independent of the educts molar ratios because the only products are IF(R_fCOO)₄.In order to stabilize iodine (V) derivates with bifunctional chelating oxo ligands we applicated bis(trimethylsilyl) pinacolate, and in smooth reactions we yielded IF₃[OC(CH₃)₂C(CH₃)₂O] and IF[OC(CH₃)₂  C(CH₃)₂O]₂, in which iodine is part of five membered heterocyclic rings. The ¹⁹F-nmr-spectra are consistent with the diolate occupying the axiale and equatorial positions.An extension of the silyl method is the new synthesis of C₆F₅IF₄ which could be obtained in the smooth reaction of IF₅ with stochiometric amounts of Si(C₆F₅)₄.     

Bis(fluorobenzoyloxy)methylphosphansulfide

Bis(fluorobenzoyloxy)methyl phosphane sulfides CH₃P(S) [OC(O)R]₂ [R = C₆H₄-2-F (1), C₆H₄-3-F (2), C₆H₄-4-F (3), C₆H₃-2,6-F₂ (4), and C₆F₅ (5)] were prepared by treating silver salts of carboxylic acids AgOC(O)R with CH₃P(S)Cl₂ and characterised by IR- and NMR-spectroscopy. Compared to bis(fluorobenzoyloxy)methylphosphane oxides, there is less tendency towards formation of symmetrical anhydrides and greater stability to hydrolysis.     

The oxygen Kα x-ray emission spectra of fluorinated anisoles and pentafluorophenol

Oxygen and fluorine K_α X-ray emission spectra have been obtained for a number of oxygen-containing compounds: H₂O, CH₃OH, C₆H₅OH, C₆H₅OCH₃, C₆F₅OH and 4-XC₆F₄OCH₃ (X = F, OCH₃, CF₃) in the solid or gaseous states and interpreted on the basis of the UV photoelectron and ESCA data and the results of MINDO/3 calculations. The mixing of the oxygen 2pAO with the highest occupied π-orbitals of the benzene ring is concluded to be small. The main contribution of the 2p(O)AO is shown to be to the system of σ-levels and lower-lying π-levels. CH₃OH is assumed to have hyperconjugation. Comparison of the electronic structures of oxygen in phenol and anisole with those in their polyfluorinated analogues shows the reduced effectiveness of oxygen 2pAO conjugation with the π-system of the benzene ring in the latter cases.     

Triorganoantimon- und Triorganobismutderivate von 2-Pyridincarbonsäure und 2-Pyridylessigsäure Kristall- und Molekülstrukturen von (C6H5)3Sb(O2C-2-C5H4N)2 und (CH3)3Sb(O2CCH2-2-C5H4N)2

Triorganoantimony and Triorganobismuth Derivatives of 2-Pyridinecarboxylic Acid and 2-Pyridylacetic Acid. Crystal and Molecular Structures of (C₆H₅)₃Sb(O₂C-2-C₅H₄N)₂ and (CH₃)₃Sb(O₂CCH₂-2-C₅H₄N)₂ Triorganoantimony and triorganobismuth dicarboxylates R₃M(O₂C-2-C₅H₄N)₂ (M = Sb, R = CH₃, C₆H₅, 4-CH₃OC₆H₄; M = Bi, R = C₆H₅, 4-CH₃C₆H₄) and (CH₃)₃Sb(O₂CCH₂-2-C₅H₄N)₂ have been prepared from (CH₃)₃Sb(OH)₂, R₃SbO (R = C₆H₅, 4-CH₃OC₆H₄), or R₃BiCO₃ (R = C₆H₅, 4-CH₃C₆H₄) and the appropriate heterocyclic carboxylic acid. Vibrational spectroscopic data indicate a trigonal bipyramidal environment of M the O(? C)-atoms of the carboxylate ligands being in the apical and three C atoms (of R) in the equatorial positions; in addition coordinative interaction occurs in the 2-pyridinecarboxylates between M and O(?C) of one and N of the other carboxylate ligand and in (CH₃)₃)Sb(O₂CCH₂-2-C₅H₄N)₂ between Sb and O(?C) of both carboxylate ligands. (C₆H₅)₃Sb(O₂C-2-C₅H₄N)₂/(CH₃)₃Sb(O₂CCH₂-2-C₅H₄N)₂ crystallize monoclinic [space group P2₁/c/P2₁/n; a = 892.6(9)/1043.4(6), b = 1326.9(6)/3166.2(18), c = 2233.1(9)/1147.5(7) pm, β = 99.74(8)°/97.67(5)° Z = 4/8; d(calc.) = 1.522/1.553 × Mg m^?3; V_cell = 2606.7 × 10⁶/3757.0 × 10⁶pm³, structure determination from 3798/4965 independent reflexions (F ≥ 4.0 σ(F))/(I ≥ 1.96 σ(I), R(unweighted) = 0.024/0.036]. Sb is bonding to three C₆H₅/CH₃ groups in the equatorial plane [mean distances Sb? C: 212.2(3)/208.7(6) pm] and two carboxylate ligands via O in the apical positions [Sb? O distances: 218.5(2), 209.9(2)/212.1(3), 213.2(3) pm]. In (C₆H₅)₃Sb(O₂C-2-C₅H₄N)₂ there is a short Sb? O(?C) and a short Sb? N contact [Sb? O: 272.1(2), Sb? N: 260.2(2) pm] and distoritions of the equatorial angles [C? Sb? C: 99.2(1)°, 158.2(1)°, 102.0(1).] and of the axial angle [O? Sb? O: 169.9(1)°], and in (CH₃)₃Sb(O₂CCH₂-2-C₅H₄N)₂, which contains two different molecules in the asym-metric unit, there are two Sb? O(?C) contacts [Sb? O, mean: 302.2(4), and 310.7(4)pm, respectively] and distortions of the equatorial angles [C? Sb? C: 114.5(2)°, 132.4(3)° 113.1(2)°, and 123.9(3)° 115.5(2)°, 120.6(3)°, respectively] and of the axial angles [O? Sb? O: 174,9(1)°, 177.9(1)°, respectively].     

Studies on novel unsymmetrical azomethines—III : Copper(II) complexes of unsymmetrical tetradentate azomethines

Copper(II) complexes of unsymmetrical bifunctional tetradentate azomethines having the general formulae, (OC₁₀H₆CH:NXN:C(R)C₆H₄O)Cu, (OC₁₀H₆CH:NXN:C(CH₃)CHC(CH₃)OCu, (OC₆H₄CH:NXN:C(CH₃)C₆H₄O)Cu, (OC₆H₄C(R);NXN:C(CH₃)CHC(CH₃)O)Cu (where R = H or CH₃, X = (CH₂)₃, (CH₂)₄, (CH₂)₆ or -oC₆H₄) have been synthesized by the reactions of preformed mixed imine complexes of the type, CuLL′ (where L and L′ are two different imines such as 2-hydroxy-1-naphthaldimine, salicylaldimine, o-hydroxyacetophenonimine or acetylacetonimine) with diamines such as 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane or o-phenylenediamine. These complexes have been characterized by elemental analyses, TLC, conductance, magnetic measurements, IR and electronic spectra.     

Optisch aktive übergangsmetall-komplexe LXIV. Neue optisch aktive Cp(CO)Fe-acyl-komplexe mit

The novel complexes CpFe(CO)(COR)P(C₆H₅)₂NR'R^* with Cp = C₅H₅,C₉H₇ (indenyl); R = CH₃, C₂H₅, CH(CH₃)₂, CH₂C₆H₅;R` = H, CH<sub>3</sub>, C<sub>2</sub>H<sub>5</sub>, CH<sub>2</sub>C<sub>6</sub>H<sub>5</sub> and R<sup>*</sup> = (S)-CH(CH<sub>3</sub>)(C<sub>6</sub>H<sub>5</sub>), have been synthesized by reaction of CpFe(CO)<sub>2</sub>R wiht P(C<sub>6</sub>H<sub>5</sub>)<sub>2</sub>NR`R^* and characterized analytically as well as spectroscopically. The pairs of diastereoisomers RS/SS have been separated by preparative liquid chromatography and fractional crystallization, respectively. The optically pure complexes (+)₄₃₆- und ()₄₃₆-CpFe(CO)(COR)P(C₆H₅)₂NR`R^* are configurationally stable at room temperature. At higher temperatures they equilibrate with CpFe(CO)₂R and epimerize with respect to the Fe configuration.     

Triorganoantimon- und Triorganobismutderivate von Carbonsäuren fünfgliedriger Heterocyclen Kristall- und Molekülstruktur von (C6H5)3Sb(O2C-2-C4H3S)2

Inhaltsübersicht. Triorganoantimon- und Triorganobismutdicarboxylate R₃M[O₂C(CH₂)ⁿ-2-C₄H₃X]₂ (M = Sb, R = CH₃, C₆H₁₁, C₆H₅, 4-CH₃OC₆H₄; M = Bi, R = C₆H₅, 4-CH₃C₆H₄; n = 0, X = O, S, NH, NCH₃. M = Sb, R = CH₃, C₆H₅; M = Bi, R = C₆H₅; n = 1, X = O, S. M = Sb, R = C₆H₁₁, n = 1, X = S; R = 4-FC₆H₄, n = 0, X = O, S, NCH₃; R = 2,4,6-(CH₃)₃C₆H₂, n = 0, X = O, S, NH) wurden durch Reaktionen von R₃Sb(OH)₂ (R = CH₃, C₆H₁₁, 2,4,6-(CH₃)₃C₆H₂), R₃SbO (R = C₆H₅, 4-CH₃OC₆H₄, 4-FC₆H₄) bzw. R₃BiCO₃ mit den entsprechenden fünfgliedrigen heterocyclischen Carbonsäuren 2-C₄H₃X(CH₂)_nCOOH dargestellt. Auf der Basis schwingungsspektroskopischer Daten wird für alle Verbindungen eine trigonal bipyramidale Umgebung vom M (zwei O-Atome von einzähnigen Carboxylatliganden in den apikalen, drei C-Atome von R in den äquatorialen Positionen) vorgeschlagen, ferner eine schwache Wechselwirkung zwischen O(=C) jeder Carboxylatgruppe und M. Die Kristallstrukturbestimmung von (C₆H₅)₃Sb(O₂C–2-C₄H₃S)₃ stützt diesen Vorschlag. Die Verbindung kristallisiert triklin [Raumgruppe P$1; a = 891,8(14), b = 1058,2(12), c = 1435,6(9) pm, α = 68,53(8), β = 85,47(9), γ = 85,99(11)°; Z = 2; d(ber.) = 1,607 Mg m^–3; V(Zelle) = 1255,6 ų; Strukturbestimmung anhand von 3947 unabhängigen Reflexen (F_o > 3σ(F²_o)), R(ungewichtet) = 0,037]. Sb bindet drei C₆H₅-Gruppen in der äquatorialen Ebene [mittlerer Abstand Sb–C: 211,1(5)pm] und zwei einzähnige Carboxylatliganden in den apikalen Positionen einer verzerrten trigonalen Bipyramide [mittlerer Abstand Sb–O: 212,0(4) pm]. Aus den relativ kurzen Sb – O(=C)-Abständen [274,4(4) und 294,9(4) pm] und aus der Aufweitung des dem O(=C)-Atom nächsten äquatorialen C–Sb–C-Winkels auf 145,9(2)° [andere C-Sb-C-Winkel: 104,4(2), 109,5(2)°] wird auf schwache Sb–O(=C)-Koordination geschlossen. Schließlich wird eine Korrelation zwischen dem (+, –)I-Effekt des Organoliganden R an M (M = Sb, Bi) und der Stärke der M–O(=C)-Koordination in den Dicarboxylaten R₃M[O₂C(CH₂)_n–2-C₄H₃X]₂ vorgeschlagen. Triorganoanümony and Triorganobismuth Derivatives of Carbonic Acids of Five-membered Heterocycles. Crystal and Molecular Structure of (C₆H₅)₃Sb(O₂C–2-C₄H₃S)₂ Triorganoantimony- and triorganobismuth dicarboxylates R₃M[O₂C(CH₂)_n–2-C₄H₃X]₂ (M = Sb, R = CH₃, C₆H₁₁, C₆H₅, 4-CH₃OC₆H₄; M = Bi, R = C₆H₅, 4-CH₃C₆H₄; n = 0, X = O, S, NH, NCH₃. M = Sb, R = CH₃, C₆H₅; M = Bi, R = C₆H₅; n = 1, X = O, S. M = Sb, R = C₆H₁₁, n = 1, X = S; R = 4-FC₆H₄, n = 0, X = O, S, NCH₃; R = 2,4,6-(CH₃)₃C₆H₂, n = 0, X = O, S, NH) have been prepared by reaction of R₃Sb(OH)₂ (R = CH₃, C₆H₁₁; 2,4,6-(CH₃)₃C₆H₂), R₃SbO (R = C₆H₅, 4-CH₃OC₆H₄, 4-FC₆H₄) or R₃BiCO₃ with the appropriate five-membered heterocyclic carboxylic acid. From vibrational data for all compounds a trigonal bipyramidal environment around M (two O atoms of unidendate carboxylate ligands in apical, three C atoms (of R) in equatorial positions) is proposed and also an additional weak interaction of O(=C) of each carboxylate group and M. The crystal structure determination of Ph₃Sb(O₂C–2-C₄H₃S)₂ gives additional prove to this proposal. It crystallizes triclinic [space group P$1; a = 891.8(14), b = 1058.2(12), c = 1435.6(9) pm, α = 68.53(8), β = 85.47(9), γ = 85.99(11)°; Z = 2; d(calc.) = 1.607 Mg m^–3; V_cell = 1255.6 ų; structure determination from 3 947 independent reflexions (F_o > 3σ(F²_o)), R(unweighted) = 0.037]. Sb is bonding to three C₆H₅ groups in the equatorial plane [mean distance Sb–C: 211.1(5) pm] and two unidentate carboxylate ligands in the apical positions of a distorted trigonal bipyramid [mean distance Sb–O: 212.0(4) pm]. From the relatively short Sb–O(=C) distances [274.4(4) and 294.9(4) pm] and from the enlarged value of the equatorial C–Sb–C angle next to the O(=C) atom [145.9(2)°; other C–Sb–C angles: 104.4(2), 109.5(2)°] additional weak Sb–O(=C) coordination is inferred. Finally a correlation between the (+, –) I-effect of the organic ligands It at M and the strength of the M–O = C interaction is suggested.     

Reactions of (η5-C5H5)2Tir compounds with organic cyanides

The syntheses and properties of the titanium(III) complexes Cp₂Tir · R′CN (R = C₆H₅, o-, m-, p-CH₃C₆H₄, CH₂C₆H₅, C₆F₅, Cl; R′ = CH₃, t-C₄H₉, C₆H₅, o-CH₃C₆H₄, 2,6-(CH₃)₂C₆H₃) are described. In the complexes the nitrogen atom of the cyanide ligands is coordinated to the metal. The thermal stabilities of the complexes depend markedly on R and R′; on heating they undergo a novel reaction in which two cyanide ligands are coupled by formation of a CC bond, while the metal is oxidized to titanium(IV).     

Reactions of alkylcobalt complexes containing a tetradentate nitrogen-donating ligand

The reactions of RCo(BDM1,3pn)(H₂O) with light, heat, acids, electrophiles and nucleophiles were studied. (HBDM1,3pn is a mononegative, tetradentate dioxime-diimine ligand formed by condensing 2,3-butanedionemonoxime with 1,3-propanediamine in a 2/1 molar ratio; R = CH₃, C₂H₅, n-C₃H₇, n-C₄H₉, and C₆H₃CH_2-) Pyrolysis and photolysis of the alkyl complexes result in a cobalt(II) complex (anaerobic conditions) along with alkenes and alkanes. The major organic products from solid state pyrolysis at 200°C or photolysis in water are CH₄ (R = CH₃), C₂H₄ (R = C₂H₅), C₃H₆ (R = n-C₃H₇), C₄H₈ (R = n-C₄H₉) and (C₆H₅CH₂)₂ (R = C₆H₅CH₂). No alkyl—cobalt bond cleavage occurs with acids or bases in most cases. Two exceptions are the reactions with 3 M HNO₃ at 25°C and with 1 M NaOH at 52°C. Electrophiles like I₂ cleave the alkyl—cobalt bond forming RI and Co^III (BDM1,3pn)I₂. Nucleophilic reagents (N^-) displace the H₂O trans to the alkyl group to form RCo(BDM1,3pn)(N), but do not dealkylate the alkyl complex under the reaction conditions studied.     

Perfluoro and polyfluoroalkanesulfonic acid: XVII. Difluoromethyl perfluoroalkanesulfonates and their reactions

In contrast to R_FSO₃CH₂R(1)(R=hydrogen, alkyl and perfluoroalkyl) and R_FSO₃CF₂R_F′ (2), the reactions of difluoromethyl perfluoroalkanesulfonates RFSO₃CF₂H (3) With nucleophiles are more complicated. Halide inos, X^? (X = F, Cl, I) and ethanol only attack the alkoxyl carbon atom, cleaving the C? O bond to give HCF₂X (4) and HCF₂OEt (5) respectively. Other reagents such as RCO₂^? (R=CH₃, CF₃), C₆H₅S^? etc. can either attack the carbon or sulfur atom of 3 to give the corresponding products of C? O and S? O bond cleavages. More basic nucleophiles RO^? (R = C₆H₅, Et) mainly abstract the proton of the HCF₂ moiety to produce difluorocarbene. Ether and benzene, which can be alkylated by methyl perfluoroalkanesulfonate, do not react with 3 under similar conditions. The reaction rate of 3 with KF is much slower than that of 1 (R = H). All these data seem to indicate that the shielding effect caused by the two fluorine atoms on the methyl carbon in 3 prevents to some extent the nucleophilic attack on this carbon, but not so completely as in 2 due to the presence of a hydrogen atom.     

Syntheses and Spectroscopic Study of Some New N‐4‐Fluorobenzoyl Phosphoric Triamides; Crystal Structures of 4‐F‐C6H4C(O)N(H)P(O)R2, R = NH‐C(CH3)3, NH‐CH2C6H5, N(CH3)(CH2C6H5)

Some new N‐4‐Fluorobenzoyl phosphoric triamides with formula 4‐F‐C₆H₄C(O)N(H)P(O)X₂, X = NH‐C(CH₃)₃ ( 1 ), NH‐CH₂‐CH=CH₂ ( 2 ), NH‐CH₂C₆H₅ ( 3 ), N(CH₃)(C₆H₅) ( 4 ), NH‐CH(CH₃)(C₆H₅) ( 5 ) were synthesized and characterized by ¹H, ¹³C, ³¹P NMR, IR and Mass spectroscopy and elemental analysis. The structures of compounds 1 , 3 and 4 were investigated by X‐ray crystallography. The P=O and C=O bonds in these compounds are anti. Compounds 1 and 3 form one dimensional polymeric chain produced by intra‐ and intermolecular ‐P=O···H‐N‐ hydrogen bonds. Compound 4 forms only a centrosymmetric dimer in the crystalline lattice via two equal ‐P=O···H‐N‐ hydrogen bonds. ¹H and ¹³C NMR spectra show two series of signals for the two amine groups in compound 1 . This is also observed for the two α‐methylbenzylamine groups in 5 due to the presence of chiral carbon atom in molecule. ¹³C NMR spectrum of compound 4 shows that ²J(P,C_aliphatic) coupling constant for CH₂ group is greater than for CH₃ in agreement with our previous study. Mass spectra of compounds 1 ‐ 3 (containing 4‐F‐C₆H₄C(O)N(H)P(O) moiety) indicate the fragments of amidophosphoric acid and 4‐F‐C₆H₄CN⁺ that formed in a pseudo McLafferty rearrangement pathway. Also, the fragments of aliphatic amines have high intensity in mass spectra.