Syntheses,characterization, and crystal structures of ruthenium(II)/(III) complexes with tridentate salicylaldiminato ligands

Treatment of [Ru(PPh₃)₃Cl₂] with one equivalent of tridentate Schiff base 2-[(2-dimethylamino-ethylimino)-methyl]-phenol (HL) in the presence of triethylamine afforded a ruthenium(III) complex [RuCl₃(κ²-N,N-NH₂CH₂CH₂NMe₂)(PPh₃)] as a result of decomposition of HL. Interaction of HL and one equivalent of [RuHCl(CO)(PPh₃)₃], [Ru(CO)₂Cl₂] or [Ru(tht)₄Cl₂] (tht = tetrahydrothiophene) under different conditions led to isolation of the corresponding ruthenium(II) complexes [RuCl(κ³-N,N,O-L)(CO)(PPh₃)] (2), [RuCl(κ³-N,N,O-L)(CO)₂] (3), and a ruthenium(III) complex [RuCl₂(κ³-N,N,O-L)(tht)] (4), respectively. Molecular structures of 1·CH₂Cl₂, 2·CH₂Cl₂, 3 and 4 have been determined by single-crystal X-ray diffraction.     

A criterion for the confluence of two seams of conical intersection in triatomic molecules

It is shown that the cross product t ^{I J} (R _x )≡g ^{I J} (R _x )×h ^{I J} (R _x ), where g _τ ^{I J} (R)=(c ^I (R _x )−c ^J (c ^I (R _x )+c ^J (R _x )), h _τ ^{I J} (R)=c ^I (R _x )^† c ^J (R _x ), τ is an internal nuclear coordinate, the c ^I (R) satisfy [H(R)−E _I (R)]c ^I (R)=0 and H(R) is the electronic Hamiltonian matrix, is a unique property of a conical intersection at R _x . t ^{I J} (R _x )=0 when R _x is located at the intersection of two (or more) seams of conical intersection. This criterion for an intersection of two seams of conical intersection has important implications for algorithms that seek to locate such points. Here it␣is␣used to analyze the trifurcation of a generic C_2v ^2S+1 A−^2S+1 B seam of conical intersection, analogous to those recently found in AlH₂ and CH₂. Received: 31 July 1997 / Accepted: 27 August 1997     

Kinetics and mechanisms of homogeneous catalytic reactions. Part 8. Regioselective reduction of benzo[ b ]thiophene catalyzed by OsH(CO)(κ3-OCOCH3)(PPh3)2

The complex OsH(CO)(κ³-OCOCH₃)(PPh₃)₂ (1) catalyzes the reduction of benzo[b]thiophene (BT) to 2,3-dihydrobenzo[b]thiophene (DHBT), under mild reaction conditions. A kinetic study lead to the rate law: r = K ₁ K ₂ k ₃ /{1 + K ₁ (1+K ₂ )[BT]}[Os][BT][H₂]. A catalytic cycle was proposed, which involves the oxidative addition of hydrogen as rate-determining step.     

Synthesis and Reactions of New Fused Heterocycles Derived from 5-Substituted-4-Amino-3-Mercapto-(4H)-1,2,4-Triazole with Biological Interest

The reaction of thiocarbohydrazide with carboxylic acids at the melting temperature allows an improved preparation of 5-substituted-4-amino-3-mercapto 1,2,4-triazoles 1 _{a ? g} . Compound 1 _a reacted with 2-bromopropionic acid to give acid derivative 2 . The latter was reacted with a mixture of acetic anhydride and triethylamine to afford the mesoionic compound 3 . Heating of compound 3 in ethanol gave the ester derivative 4 , which on alkaline hydrolysis in methanol gave ketone derivative 5 . Substituted 1,2,4-triazolo [3,4-b]-6H-1,3,4-thiadiazine 6 _h,i and 7 were synthesized by reaction of 1 _a with acetylacetone, ethyl acetoacetate and chloroacetamide. Heterocyclic systems 8 and 9 were prepared through the reaction of 1 _a with 2,3-dichloro-1,4-naphthoquinone and 2,3-dichloroquinoxaline. In addition, thenoyl isothiocyanate, thenoyl chloride, 2-thiophenecarbaldehyde, and p-chlorophenyl isocyanate reacted with compound 1 _a to afford 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole ring system 10 , 11 , and urea derivative 12 . 1,2,4-Triazolo[3,4-b]-5H-pyrazole derivatives 14 _j,k were prepared through the reaction of compound 1 _a with 3-chloro-2,4-pentandione and ethyl-2-chloroacetoacetate. Compound 14 _j was treated with hydrazine to afford products 15 , 16 , and 17 depending on the type of hydrazine derivative and reaction conditions. Compound 19 was synthesized by refluxing of compound 14 _j with hydroxylamine hydrochloride to afford the corresponding oxime derivative 18 followed by treatment with thenoyl chloride.     

Liquid crystalline guanidinium phenylalkoxybenzoates: towards room temperature liquid crystals via bending of the mesogenic core and the use of triflate counter ions

A series of guanidinium salts 1(C _n ) _m –4(C _n ) _m ?X bearing phenyl alkoxybenzoate cores have been synthesised and their mesomorphic properties have been investigated by polarising optical microscopy (POM), differential scanning calorimetry (DSC) and powder X-ray diffraction experiments (small-angle X-ray scattering and wide-angle X-ray scattering). While compounds 1(C₁₂)₁?X and 3(C₁₂)₁?X with one alkoxy chain showed smectic A (SmA) phases irrespective of the counter ion, compounds 1(C₁₂)₂?OTf and 3(C₁₂)₂?OTf with two alkoxy chains displayed SmA phases and the corresponding chlorides 1(C₁₂)₂?Cl and 3(C₁₂)₂?Cl displayed Col_h. Guanidinium salts 1(C _n )₃–4(C _n )₃?X with three alkoxy chains showed Col_h phases. Whereas the use of cyclic guanidinium head groups rather than acyclic ones had only a minor influence on the mesophase properties, melting points were significantly decreased by bent core units instead of linear core units. Replacement of chloride counterions by triflate lead to a further depression of the clearing points and shifted the mesophase towards room temperature.     

Mono-Heteroatom Effects on Singlet–Triplet Energy Gaps of Divalent Five-Membered Ring XC3H3C (X = CH,N, P,and As)

Heteroatom effects were investigated on singlet–triplet energy gaps of divalent five-membered ring XC ₃ H ₃ C, 1 _X and 2 _X (X = CH, N, P, and As) at B3LYP/6-311++G?? level. All triplet states of 1 _X and 2 _X are more stable than the related singlet state. Δ G _{s ? t} between singlet and triplet states of 1 _X and 2 _X were changed in the order (in kcal/mol): 1 _As (14.43) > 1 _P (10.07) > 1 _CH (9.60) > 1 _N (8.50) and 2 _N (11.56) > 2 _CH (9.60) > 2 _P (3.07) > 2 _As (2.13).     

Syntheses and structures of cobalt(II), nickel(II), and copper(II) complexes with N,N,N′,N′-tetraalkylpyridine-2,6-dicarboxamides (O-daap) containing nitrate as the counter ion

Reactions of M(NO₃)₂?·?xH₂O [M?=?Co(II), Ni(II), and Cu(II)] with N,N,N′,N′-tetraalkylpyridine-2,6-dicarboxamides(O-daap) in CH₃CN yield [Co(O-dmap)(NO₃)₂] (1), [Co(O-deap)(NO₃)₂] (2), [Co(O-dpap)(NO₃)₂] (3), [Ni(O-dmap)(H₂O)₃](NO₃)₂] (4), [Ni(O-deap)(H₂O)₂(NO₃)](NO₃)] (5), [Cu(O-deap)(NO₃)₂] (6), and [Cu(O-dpap)(NO₃)₂] (7). X-ray crystal structures of 1, 2, 4, 5, and 7 reveal that O-daap ligands coordinate tridentate to each metal, O–N–O, with nitrate playing a vital role in molecular and crystal structures of all the complexes. The coordination geometry in the two Co(II) complexes, 1 and 2, is approximately pentagonal bipyramidal with nitrate bonded in a slightly unsymmetrical bidentate chelating mode. [Ni(dmap)(H₂O)₃](NO₃)₂ (4) and [Ni(deap)(H₂O)₂(NO₃)](NO₃) (5) exhibit octahedral geometry, the former containing uncoordinated nitrate while the latter has one nitrate coordinated unidentate and the other nitrate outside the coordination sphere. The Cu(II) in [Cu(dpap)(NO₃)₂] (7) occupies a distorted square pyramidal geometry and is linked to two unidentate nitrates, although one nitrate is also involved in a weak interaction with the metal through its other oxygen. IR spectra and other physical studies are consistent with their crystal structural data. O-dmap?=?N,N,N′,N′-tetramethylpyridine-2,6-dicarboxamides; O-deap?=?N,N,N′,N′-tetraethylpyridine-2,6-dicarboxamides; and O-dpap?=?N,N,N′,N′-tetraisopropylpyridine-2,6-dicarboxamides.     

Polymerizations of methyl methacrylate and rac-lactide by zinc(II) precatalyst containing N-substituted 2-iminomethylpyridine and 2-iminomethylquinoline

The reaction of [ZnCl₂] with N-cyclopentyl-1-(quinolin-2-yl)methanimine (L_A), N-cyclohexyl-1-(quinolin-2-yl)methanimine (L_B), N-cyclohexyl-1-(pyridin-2-yl)methanimine (L_C), 2,6-diethyl-N-(pyridin-2-ylmethylene)aniline (L_D), N-cyclopentyl-1-(pyridin-2-yl)methanimine (L_E), and N-phenyl-(pyridin-2-yl)methanimine (L_F) in ethanol produced the bidentate [(NN′)ZnCl₂] complexes, [L_AZnCl₂], [L_BZnCl₂], [L_CZnCl₂], [L_DZnCl₂], [L_EZnCl₂] and [L_FZnCl₂], respectively. The molecular structures revealed that the zinc in [L_nZnCl₂] (L_n = L_A ? L_D) showed a distorted tetrahedral geometry involving two nitrogens of N,N’-bidentate ligands and two chloride ligands. Most of these initiators were effective for polymerization of methyl methacrylate (MMA) and polymerization of rac-lactide (rac-LA). [L_CZnCl₂] (with N-cyclohexyl substituted at imine-pyridine moiety) exhibited the highest catalytic activity for MMA polymerization in the presence of modified methylaluminoxane (MMAO) with an activity of 3.33 × 10⁴ g PMMA/mol·Zn·h at 60 °C, giving moderate syndiotactic poly methyl methacrylate (PMMA) with high molecular weight (9.62 × 10⁵ g/mol). The dimethyl derivatives [L_nZnMe₂] (L_n = L_A ? L_F), generated in situ, polymerized rac-LA with moderate activity and yielded a polylactide (PLA) with good number-average molecular weights and narrower polydispersity indices (PDIs). [L_AZnMe₂] effectively initiates the ring-opening polymerization (ROP) of rac-LA to attain heterotactic PLA (P_r = 0.91).     

Synthesis,structure and methyl methacrylate polymerization of cobalt(II), zinc(II) and cadmium(II) complexes with N,N′,N-bidentate versus N,N′,N-tridentate N,N′,N-bis((1H-pyrazol-1-yl)methyl)amines

Mononuclear Co(II), Zn(II) and Cd(II) complexes derived from bidentate or tridentate N,N′,N-bis((1H-pyrazol-1-yl)methyl)amines (L_n = L_A, L_B), where L_A is N,N-bis((1H-pyrazol-1-yl)methyl)-3-methoxypropan-1-amine and L_B is 3-methoxy-N,N-bis((3,5-dimethyl-1H-pyrazol-1-yl)methyl)propan-1-amine, have been synthesized and characterized. The geometry at Co(II) and Cd(II) for [L_ACoCl₂], [L_BCoCl₂] and [L_BCdBr₂] with N,N′,N-tridentate ligands (L_n = L_A, L_B) can be described as a distorted trigonal bipyramid achieved by coordinative interaction of N_pyrazole, two halides and the nitrogen of amine moiety. However, the molecular structure of four-coordinate [L_AZnCl₂] can be best described as tetrahedral, resulting in an eight-membered chelate ring. [L_ACoCl₂] polymerized methyl methacrylate in the presence of modified methylaluminoxane at 60 °C and resulted in poly(methylmethacrylate) (PMMA) with higher molecular weight and narrower polydispersity index compared to the other synthesized complexes. However, all the synthesized complexes yielded syndiospecific PMMA, characterized using ¹H NMR spectroscopy, with ca. 0.70.     

Syntheses,structures, and thermal properties of new Au(III) organometallic compounds with ancillary S-, O-, and/or N-donor ligands

((CH₃)₂Au)₂C₂O₄ (1), ((CH₃)₂AuSCN)₂ (2), (CH₃)₂AuSSP(OCH₃)₂ (3), and (CH₃)₂AuSSP(OC₂H₅)₂ (4) were prepared and recrystallized from hexane to determine their crystal structures and analyze them by thermal methods (TGA). The compounds have been investigated as new possible precursors for metal–organic chemical vapor deposition (MOCVD). Compounds 1 and 2 are solids, while 3 and 4 are liquids. Crystal structures of 1 and 2 have been studied by single-crystal X-ray diffraction (XRD): compounds are monoclinic, space group for 1 P2₁/c, for 2 P2₁/n. Compound 1 has crystal parameters a?=?7.6952(5)?Å, b?=?11.1814(8)?Å, c?=?12.2893(8)?Å, α?=?90°, β?=?104.922(4)°, γ?=?90°; 2 has crystal parameters a?=?5.6184(3)?Å, b?=?15.2744(6)?Å, c?=?6.9202(3)?Å, α?=?90°, β?=?102.864(2)°, γ?=?90°. These are neutral complexes, in which molecules are only connected by van der Waal's interactions. Thermal gravimetric analyses (TGA) have shown that 3 and 4 evaporate practically without decomposition. MOCVD experiments were carried out at lower pressure using 3 and 4 as precursors. The films were grown on Si substrate and investigated by XRD and SEM.     

Syntheses,structural characteristics,and antimicrobial activities of new organotin(IV) 3-(4-bromophenyl)-2-ethylacrylates

New organotin(IV) carboxylates, [n-Bu₂SnL₂] (1), [Et₂SnL₂] (2), [Me₂SnL₂] (3), [n-Oct₂SnL₂] (4), [n-Bu₃SnL] _n (5), [Me₃SnL] _n (6), and [Ph₃SnL] _n (7), where L?=?3-(4-bromophenyl)-2-ethylacrylate, were synthesized and characterized by elemental analysis, FT-IR, and multinuclear NMR (¹H, ¹³C, and ¹¹⁹Sn). Spectroscopic studies confirm coordination of L to the organotin moiety via COO group. Single-crystal X-ray analysis reveals bridging mode of coordination in 6. Packing diagram established a supramolecular cage-like structure for 6 due to Sn–O interactions (3.287?Å). Subsequent antimicrobial activities proved them to be active biologically.     

Ethylene/1-hexene copolymerization by salicylaldiminato vanadium(III) complexes activated with diethylaluminum chloride

Mono salicylaldiminato vanadium（Ⅲ） complexes（1a-1f）[RN = CH（ArO）]VCl₂（THF）₂（Ar = C₆H₄（1a-1e）,R = Ph,1a;R = p-CF₃Ph,1b;R = 2,6-Me₂Ph,1c;R = 2,6-iPr₂Ph,1d;R = cyclohexyl,1e;Ar = C₆H₂tBu₂（2,4）,R = 2,6-iPr₂Ph, 1f） and bis（salicylaldiminato） vanadium（Ⅲ） complexes（2a-2f）[RN = CH（ArO）]₂VCl（THF）_x（Ar = C₆H₄（2a-2e）,x = 1 （2a-2e）,R = Ph,2a;R =p-CF₃Ph,2b;R = 2,6-Me₂Ph,2c;R = 2,6-iPr₂Ph,2d;R = cyclohexyl,2e;Ar = C₆H₂tBu₂（2,4）,R = 2,6-iPr₂Ph,x = 0,2f） have been evaluated as the active catalysts for ethylene/1-hexene copolymerization in the presence of Et₂AlCl.The ligand substitution pattern and the catalyst structure model significantly influenced the polymerization behaviors such as the catalytic activity,the molecular weight and molecular weight distribution of the copolymers etc.The highest catalytic activity of 8.82 kg PE/（mmol_V·h） was observed for vanadium catalyst 2d with two 2,6-diisopropylphenyl substituted salicylaldiminato ligands.The copolymer with the highest molecular weight was obtained by using mono salicylaldiminato vanadium catalyst 1f having ligands with tert-butyl at the ortho and para of the aryloxy moiety.     

Crystal structures of the novel hydrated borates Ba2B5O9(OH), Sr2B5O9(OH) and Li2Sr8B22O41(OH)2

Three novel hydrated borates Ba₂B₅O₉(OH) (1), Sr₂B₅O₉(OH) (2) and Li₂Sr₈B₂₂O₄₁(OH)₂ (3) have been synthesized hydrothermally and their structures determined. Compounds (1) and (2) are isostructural, crystallizing in space group P2₁/c and having lattice parameters of a=6.6330(13) Å, b=8.6250(17) Å, c=14.680(3) Å, β=93.46(3)° and a=6.4970(13) Å, b=8.4180(17) Å, c=14.177(3) Å, β=94.35(3)°, respectively. Compound (3) crystallizes in P-1 with lattice parameters of a=6.4684(13) Å, b=8.4513(17) Å, c=14.881(3) Å, α=101.21(3)°, β=93.96(3)°, γ=90.67(3)°. While similar in their axis lengths, (3) differs greatly in structure and formulation from (1) and (2). The structure of (1) and (2) is contrasted to that of the well-known mineral hilgardite (Ca₂B₅O₉Cl·H₂O).     

Organotellurium Ligands & Their Metal Complexes: Recent Developments

Abstract

The ligand chemistry of telluroethers, halotellurium ligands, and polytellurides has received good attention in the last decade. Tellurium-containing species have been used to design clusters. In the recent past the ligation of di and tri-telluroethers (including bis(4-methoxyphenyltelluro)methane) has been studied. Hybrid organotellurium ligands, N-[2-(4-methoxyphenyltelluro)propyl]phthalimid (L ¹ ), 2-(4-ethoxyphenyltelluromethyl)-tetrahydro-2H-pyran (L ² ), 2-(2-{4-ethoxyphenyl} telluroethyl)-1,3-dioxane (L ³ ), N-{2-(4-methoxyphenyltelluro)ethyl}morpholine (L ⁴ ), N-{2-(4-methoxyphenyltelluro)ethyl}-pyrrolidine (L ⁵ ), bis{2-(pyrrolidine-N-yl)ethyl}telluride (L ⁶ ), 1-(4-methoxyphenyltelluro)-2-[3-(6-methyl-2-pyridyl) propoxy]ethane (L ⁷ ), and 2-[2-(4-methoxyphenyltelluro)ethyl]thiophene (L ⁸ ) have been designed recently and studied for their complexation reactions. The (Te, N) and (N, Te, N) ligands, L ⁵ and L ⁶ , coordinate with Hg(II) through Te and N both, but the bonding with N is some what weak. The morpholine nitrogen of L ⁴ does not coordinate with Pd(II) or Pt(II) along with Te. The L ⁷ behaving as a (Te, N) ligand has formed 20-membered metallomacrocycle ring with Pt(II). Tellurated Schiff bases 4-MeOC₆H₄TeCH₂CH₂N═C(CH₃)C₆H₄-2-OH (L ⁹ ) and 2-HO-C₆H₄-(CH₃)C═NCH₂CH₂TeCH₂CH₂N═C(CH₃)C₆H₄-2-OH (L ¹⁰ ) and their reduction products 4-MeOC₆H₄TeCH₂CH₂NHCH(CH₃)C₆H₄-2-OH (L ¹¹ ) and 2-HO-C₆H₄-(CH₃)CHNHCH₂CH₂TeCH₂CH₂NHCH(CH₃)C₆H₄-2-OH (L ¹² ) respectively have been synthesized and studied for ligation behaviour. The L ⁹ on reaction with the [Ru(p-cymene)Cl₂]₂ results in [Ru(p-cymene)(4-MeOC₆H₄TeCH₂CH₂NH₂)Cl]Cl · H₂O whereas in the reaction of L ¹⁰ with [Ru(p-cymene) Cl₂]₂, p-cymene ligand is lost resulting in [RuCl(L ¹⁰ -H)]. The recent developments, particularly designing of L ¹ to L ¹² and their ligand chemistry, are reviewed in the present paper.     

The effect of different arms on the properties of chiral branched-arm liquid crystals based on isosorbide as the chiral core

A new series of two-arm ( MA₁ , MA₂ ), four-arm ( MA₃ ) and six-arm ( MA₄ ) chiral liquid crystalline compounds containing isosorbide as the chiral core were synthesised. Four precursors of branched-arm A₁–A₄ were first obtained, and then were esterised separately with isosorbide to obtain four chiral branched-arm liquid crystals ( MA₁–MA₄ ). The structure and properties have been characterised. The results show that MA₁ was smectic–cholesteric phase with a fan-like and oily streak texture; MA₂–MA₄ showed a cholesteric phase with oily streak texture, or lined texture and finger print texture. Isosorbide successfully induced a cholesteric phase. The melting point and clearing point values for MA₁–MA₄ first increased and then decreased. The branched-arm and chiral core quantity affected the liquid crystalline properties. At the same time, the difference in side-arms resulted in different directions of rotation. MA₁–MA₂ showed right-handed rotation and had selective reflection; MA₃–MA₄ demonstrated left-handed rotation and did not have selective reflection.     

Ruthenium(II) carbonyl complexes of P,P and P,O donor diphosphine ligands,Ph2P(CH2)nPPh2 and Ph2P(CH2)nP(O)Ph2, n = 2, 3 and their activities in catalytic transfer hydrogenation reactions

The polymeric precursor [RuCl₂(CO)₂]_n reacts with the ligands, P∩P (a, b) and P∩O (c, d), in 1:1 M ratio to generate six-coordinate complexes [RuCl₂(CO)₂(?²-P∩P)] (1a, 1b) and [RuCl₂(CO)₂(?²-P∩O)] (1c, 1d), where P∩P: Ph₂P(CH₂)_nPPh₂, n = 2(a), 3(b); P∩O: Ph₂P(CH₂)_nP(O)Ph₂, n = 2(c), 3(d). The complexes are characterized by elemental analyses, mass spectrometry, thermal studies, IR, and NMR spectroscopy. 1a–1d are active in catalyzed transfer hydrogenation of acetophenone and its derivatives to corresponding alcohols with turnover frequency (TOF) of 75–290 h^?1. The complexes exhibit higher yield of hydrogenation products than catalyzed by RuCl₃ itself. Among 1a–1d, the Ru(II) complexes of bidentate phosphine (1a, 1b) show higher efficiency than their monoxide analogs (1c, 1d). However, the recycling experiments with the catalysts for hydrogenation of 4-nitroacetophenone exhibit a different trend in which the catalytic activities of 1a, 1b, and 1d decrease considerably, while 1c shows similar activity during the second run.     

DARSTELLUNG VON MERCAPTOTHIOETHERN UND BIS-MERCAPTOTHIOETHERN DURCH SPALTUNG VON THIOETHERN MIT NATRIUM IN FLÜSSIGEM AMMONIAK

Abstract

Die Spaltung von s-Trithian, Trithioacetaldehyd, (CH₂S) _n und (CH₂S₂) _n mit Natrium in flüssigem Ammoniak liefert Mercaptothioether und Bis-Mercaptothioether nach einem allgemien anwendbaren Reaktionsprinzip. Beschrieben wird die Synthese von 2.4-Dithiapentan-1-thiol (1), 2-Thiapropan-1-thiol (2), 2-Mercapto-3-thiapentan (4) und Bis-mercaptodimethylsulfid (6).

The cleavage of s-trithiane, trithio acetic aldehyde, (CH₂S) _n and (CH₂S₂) _n by sodium in liquid ammonia leads to the formation of mercapto thioethers and bis-mercapto thioethers according to a general reaction principle. Described is the synthesis of 2.4-dithiapentane-1-thiole (1), 2-thiapropane-1-thiole (2), 2-mercapto-3-thiapentane (4) and bis-mercapto dimethyl sulfide (6).     

One-Pot Synthesis and Fungicidal Activities of Derivatives of Imidazo [2,1-b]-1,3,4-thiadiazol-5(6H)-one

The isothiocyanates 2, obtained from aza-Wittig reactions of vinyliminophosphoranes 1 with CS ₂ , reacted with hydrazine to give 3-amino-2-thioxo-4-imidazolidinones 4. One-pot reactions of 4, aromatic isocyanates, Ph ₃ P, C ₂ Cl ₆ , and Et ₃ N generated imidazo[2,1-b]-1,3,4-thiadiazol-5(6H)-ones 7. Compound 7 exhibited good fungicidal activities, especially against Sclerotinia sclerotiorum de Bary and Botrytis Cinerea Pers.     

Solvent effects on the dimensionality of oxamato-bridged manganese(II) compounds

Abstract

Two new oxamate-containing manganese(II) complexes, [{Mn(H₂edpba)(H₂O)₂}₂]_n (1) and [Mn(H₂edpba)(dmso)₂]?dmso?CH₃COCH₃?H₂O (2) (H₄edpba = N,N′-ethylenediphenylenebis(oxamic acid) and dmso = dimethylsulfoxide), have been synthesized and the structures of 1 and 2 were characterized by single crystal X-ray diffraction. The structure of 1 consists of neutral honeycomb networks in which each manganese(II) is six-coordinate by one H₂edpba^2? ligand and two carboxylate–oxygens from two other H₂edpba^2? ligands building the equatorial plane. Each manganese is connected to its nearest neighbor through two carboxylate(monoprotonated oxamate) bridges in an anti-syn conformation. A dmso solution of single crystals of 1 was placed under acetone atmosphere affording 2, whereas putting 2 in equimolar water:ethanol mixture results in 1. The molecular structure of 2 is made up of mononuclear manganese(II) units which are interlinked by weak C–H?π and edge-to-face π-stacking interactions leading to supramolecular chains along the crystallographic b axis. Magnetic measurements reveal the occurrence of an antiferromagnetic coupling between two manganese(II) ions through anti-syn carboxylate bridges for 1 [J = ?1.18 cm^?1, the Hamiltonian being defined as H = ?J S₁^.S₂] and very weak intrachain ferromagnetic interactions in 2 [J = + 0.046 cm^?1, H = ?J ∑_iS_i^.S_i + 1].     

Synthesis and X-Ray Crystal Structures of Fe2Ru(CO)12−n (CNBu t ) n and FeRu2(CO)12−n (CNBu t ) n (n=1, 2)

The clusters Fe₂Ru(CO)_12–n (CNBu ^t ) _n (3, n=1; 4, n=2), FeRu₂(CO)_12–n (CNBu ^t ) _n (5, n=1, 6, n=2) and FeRu₂(CO)₁₁(CNCy) (5a) have been prepared by direct substitution from the parent carbonyl precursors Fe₂Ru(CO)₁₂ (1) and FeRu₂(CO)₁₂ (2). All compounds have been characterized spectroscopically and clusters 3, 4, 5, and 6 by single crystal X-ray determinations. In all cases, the isonitrile ligands adopt axial or pseudo-axial positions on a ruthenium atom. The structures of 3–5 are very similar to their parent clusters, but the extent of metal framework disorder is significantly less. Cluster 6 adopts the same C _2v Fe₃(CO)₁₂ type structure as 4, and thus differs markedly from the parent compound 2, which has a D ₃ structure .