Preparation of pyranylidene complexes of ruthenium

Dimerization of alkylpropiolate on the half-sandwich fragment [Ru(η5-C5H5)(PPh3){P(OMe)3}]+ affords pyranylidene derivatives

Hydrazine complexes of ruthenium with cyclopentadienyl and indenyl ligands: Preparation and reactivity

Hydrazine complexes [Ru(η5-C5H5)(RNHNH2)(PPh3){P(OMe)3}]BPh4 (1–3) and [Ru(η5-C9H7)(RNHNH2) (PPh3){P(OEt)3}]BPh4 (4–6) (R = H, Me, Ph) were prepared by allowing chloro-compounds RuCl(η5-C5H5) (PPh3)[P(OMe)3] and RuCl(η5-C9H7) (PPh3)[P(OEt)3] to react with an excess of hydrazine in refluxing ethanol. Treatment of complexes 1–6 with Pb(OAc)4 at −40 °C yielded diazene derivatives [Ru(η5-C5H5)(RNdouble bond; length as m-dashNH) (PPh3){P(OMe)3}]BPh4 (7, 8) and [Ru(η5-C9H7) (RNdouble bond; length as m-dashNH)(PPh3){P(OEt)3}]BPh4 (10, 11) (R = Me, Ph). Aryldiazene complexes [Ru(η5-C5H5)(RNdouble bond; length as m-dashNH)(PPh3){P(OMe)3}]BPh4 (8, 9) (R = Ph, p-tolyl) were also prepared by allowing hydride RuH(η5-C5H5)(PPh3)[P(OMe)3] to react with aryldiazonium salts [RN2]+BF4– in CH2Cl2. The complexes were characterised by spectroscopy (IR, 1H, 31P NMR) and X-ray crystal structure determination of [Ru(η5-C9H7)(PhNHNH2)(PPh3){P(OEt)3}]BPh4 (6) The preparation of half-sandwich hydrazine complexes of ruthenium stabilised by cyclopentadienyl and indenyl ligands is described. Related diazene derivatives were obtained by both selective oxidation of coordinated hydrazine and insertion of aryldiazonium cations into the Ru–H bond of the hydride precursor

Hydrolysis of Coordinated Diazoalkanes To Yield Side-On 1,2-Diazene Derivatives

Diazoalkane complexes [Ru(eta(5)-C5Me5)(N(2)CAr1Ar2)(PPh3){P(OR)(3)}]BPh4 [R = Me (1), Et (2); Ar1 = Ar2 = Ph (a); Ar1 = Ph, Ar2 = p-tolyl (b); Ar1Ar2 = C12H8 (c)] were prepared by allowing chloro complexes RuCl(eta(5)-(CMe5)-Me-5)(PPh3)[P(OR)(3)] to react with diazoalkane Ar1Ar2CN2 in ethanol. The treatment of compounds 1 and 2 with (HO)-O-2 afforded 1,2-diazene derivatives [Ru eta(5)-C5Me5)(eta(2)-NH-NH)(PPh3){P(OR)(3)}]BPh4 (3 and 4) and ketone Ar1Ar2CO. A reaction path involving nucleophilic attack by H2O on the coordinated diazoalkane is proposed. The complexes were characterized spectroscopically (IR and NMR) and by X-ray crystal structure determination of [Ru(eta(5)-C5Me5)(eta(2)-NH-NH)(PPh3){P(OMe)(3)}]BPh4 (3)

Pentamethylcyclopentadienyl Half-Sandwich Diazoalkane Complexes of Ruthenium: Preparation and Reactivity

The diazoalkane complexes [Ru(eta(5)-C5Me5)(N(2)CAr1Ar2){P(OR)(3)}L]BPh4 (1-4) [R = Me, L = P(OMe)(3) (1); R = Et, L = P(OEt)(3) (2); R = Me, L = PPh3 (3); R = Et, L = PPh3 (4); Arl = Ar2 = Ph (a); Arl = Ph, Ar2 = p-tolyl (b); ArlAr2 = C12H8 (c); Arl = Ph, Ar2 = PhC(O) (d)] and [Ru(eta(5)-C5Me5){N2C(C12H8)}{PPh(OEt)(2)}(PPh3)]BPh4 (5c) were prepared by allowing chloro-compounds RuCl(eta(5)-C5Me5)[P(OR)(3)]L to react with the diazoalkane Ar1Ar2CN(2) in the presence of NaBPh4. Treatment of complexes 1-4 with H2O afforded 1,2-diazene derivatives [Ru(eta(5)-C5Me5)(eta(2)-NH=NH){P(OR)(3)}L]BPh4 (6-9) and ketone Ar1Ar2CO. A reaction path involving nucleophilic attack by H2O on the coordinated diazoalkane is proposed and supported by density functional theory calculations. The complexes were characterized spectroscopically (IR and H-1, P-31, C-13, N-15 NMR) and by X-ray crystal structure determination of [Ru(eta(5)-C5Me5)(N2CC12H8){P(OEt)(3)}(2)]BPh4 (2c) and [Ru(eta(5)-C5Me5)(eta(2)-NH=NH){P(OEt)(3)}(2)]BPh4 (7)

Preparation of Diazoalkane Complexes of Ruthenium and Their Cyclization Reactions with Alkenes and Alkynes

The diazoalkane complexes [Ru(η5 -C5H5)- (N2CAr1Ar2)(PPh3)(L)]BPh4 (1−5: Ar1 = Ar2 = Ph (a), Ar1 = Ph and Ar2 = p-tolyl (b), Ar1Ar2 = C12H8 (c), Ar1 = Ph and Ar2 = PhCO (d); L = PPh3 (1), P(OMe)3 (2), P(OEt)3 (3), PPh(OEt)2 (4), But NC (5)) were prepared by allowing the chloro compounds RuCl(η5 -C5H5)(PPh3)(L) to react with the diazoalkanes Ar1Ar2CN2 in ethanol. Treatment of complexes 1−5 with ethylene (CH2CH2) under mild conditions (1 atm, room temperature) led not only to the η2 -ethylene complexes [Ru(η5 -C5H5)(η2 -CH2CH2)(PPh3)(L)]BPh4 (10−14) but also to dipolar (3 + 2) cycloaddition, affording the 4,5-dihydro-3H-pyrazole derivatives [Ru(η5 -C5H5){η1 -N NC(Ar1Ar2)CH2CH2}(PPh3)(L)]BPh4 (6−9). Acrylonitrile (CH2C(H)CN) reacted with diazoalkane complexes 2 and 3 to give the 1H-pyrazoline derivatives [Ru(η5 -C5H5){η1 -NC(CN)CH2C(Ar1Ar2)NH}(PPh3)(L)]BPh4 (19, 20). However, reactions with propylene (CH2C(H)CH3), maleic anhydride (ma, CHCHCO(O)CO) and dimethyl maleate (dmm, CH3OCOCHCHOCOCH3) led to the η2 -alkene complexes [Ru(η5 -C5H5)(η2 -R1CHCHR2)(PPh3)(L)]BPh4 (17−22). Treatment of the diazoalkane complexes 1 and 2 with acetylene CHCH under mild conditions (1 atm, room temperature) led to dipolar cycloaddition, affording the 3H-pyrazole complexes [Ru(η5 -C5H5){η1 -NNC(Ar1Ar2)CHCH}(PPh3) {P(OMe)3}]BPh4 (24), whereas reactions with the terminal alkynes PhCCH and But CCH gave the vinylidene derivatives [Ru(η5 -C5H5){CC(H)R}(PPh3){P(OMe)3}]BPh4 (25, 26). The alkyl propiolates HCCCOOR1 (R1 = Me, Et) also reacted with complexes 2 to give the 3H-pyrazole complexes [Ru(η5 -C5H5){η1 -NNC(Ar1Ar2)C(COOR1)CH}(PPh3)- {P(OMe)3}]BPh4 (27, 28). The complexes were characterized by spectroscopy and by X-ray crystal structure determinations of [Ru(η5 -C5H5){η1 -NC(CN)CH2C(Ph)(p-tolyl)NH}(PPh3){P(OMe)3}]BPh4 (19b), [Ru(η5 -C5H5){η2 -CHCHCO(O)CO}- (PPh3){P(OMe)3}]BPh4 (21), and [Ru(η5 -C5H5){η1 -NNC(C12H8)CHCH}(PPh3){P(OMe)3}]BPh4 (24c)

Reactivity with alkene and alkyne of pentamethylcyclopentadienyl half-sandwich diazoalkane complexes of ruthenium

Treatment of diazoalkane complexes [Ru(eta(5)-C5Me5)(N(2)CAr1Ar2){P(OR)(3)}L]BPh4 (1-5) [Ar1=Ar2=Ph, Ar1=Ph, Ar2=p-tolyl, Ar1Ar2=C12H8; R=Me, Et; L=P(OR)(3), PPh3] with ethylene and maleic anhydride (ma) afforded eta(2)-alkene derivatives [Ru(eta(5)-C5Me5)(eta(2)-CH2=CH2){P(OR)(3)}(PPh3)]BPh4 (7, 8) and [Ru(eta(5)-C5Me5)(eta(2)-ma){P(OR)(3)}L]BPh4 (6, 9), respectively. Acrylonitrile also reacted with diazoalkane complexes 1-5 to give dipolar (3 + 2) cycloaddition, affording 3H-pyrazole derivatives [Ru(eta(C5Me5)-C-5){eta(1)=N=NC(C12H8)CH=CH}{P(OR)(3)}(PPh3)]BPh4 [A] and [Ru(eta(5)-C5Me5) {P(OR)(3)}(PPh3)]BPh4 [B] (10, 11). Treatment of complexes 1-5 with acetylene HC = CH under mild conditions (1 atm, room temperature) led to dipolar cycloaddition, affording 3H-pyrazole complexes [Ru(eta(C5Me5)-C-5) (eta(1)-}{eta(1)=N=NC(Ar1Ar2)CH=CH}{P(OR)3} L] BPh4 (12, 15), whereas reaction with terminal alkynes HC= CR gave vinylidene derivatives [Ru(eta(5)-C5Me5){=C=C(H)R}{P(OR)(3)}L]BPh4 (13, 14, 16, 17). The complexes were characterised spectroscopically (IR and H-1, P-31, C-13 NMR) and by X-ray crystal structure determination of [Ru(eta(5)-C5Me5){eta(1)=N=NC(C12H8)CH=CH}{P(OEt)(3)}(2)]BPh4 (12). A DFT study on the reaction of diazoalkane complexes with CH2=CH2 is also reported. (C) 2016 Elsevier B. V. All rights reserved

An analytical and numerical investigation of auxeticity in cubic crystals and frameworks

Negative Poisson’s ratio, or auxetic, materials present the possibility of designing structures and components with tailored or enhanced mechanical properties. This thesis explores the phenomenon of auxetic behaviour in cubic crystals using classical and quantum modelling techniques and assesses the validity of these techniques when predicting auxetic behaviour in cubic elemental metals. These techniques are then used to explore the mechanism of this behaviour. The findings of the atomistic modelling are then used as a template to create networks of bending beams with tailored Poisson’s ratio behaviour.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Preparation of Diazoalkane Complexes of Iron(II)

Diazoalkane complexes [Fe(eta(5)-C5H5)(N(2)CAr1Ar2)(P-P)]BPh4 (1, 2) [P-P = Ph2PCH2CH2PPh2 (dppe) (1), Ph2PCH2CH2CH2PPh2 (dppp) (2); Ar1 = Ar2 = Ph (a); Ar1 = Ph, Ar2 = p-tolyl (b); Ar1Ar2 = C12H8 (c)] were prepared by allowing chloro compounds FeCl(eta(5)-C5H5)(P-P) to react with diazoalkane in the presence of NaBPh4. Phosphine complex [Fe(eta(5)-C5H5)(dppe)(kappa(1)-PPh2CH2CH2PPh2)]BPh4 (3) was also prepared. Treatment of diazoalkane complexes 1, 2 with acrylonitrile afforded 3H-pyrazole derivatives [Fe(eta(5)- C5H5)-{N=NC(Ar1Ar2)(CH(CN)CH2}(P-P)]BPh4 (4, 5), as well as a small amount of nitrile complex [Fe(eta(5)-C5H5)(kappa(1)-NCC(H)]= CH2)(P-P)]BPh4 (6). The complexes were characterised spectroscopically (IR, NMR) and by X-ray crystal structure determination of [Fe(eta(5)-C5H5){N2C(C12H8)}(dppe)]BPh4 (1c)

Hydrolysis of Coordinated Diazoalkanes To Yield Side-On 1,2-Diazene Derivatives

Diazoalkane complexes [Ru­(η⁵-C₅Me₅)­(N₂CAr1Ar2)­(PPh₃)­{P­(OR)₃}]­BPh₄ [R = Me (<b>1</b>), Et (<b>2</b>); Ar1 = Ar2 = Ph (<b>a</b>); Ar1 = Ph, Ar2 = <i>p</i>-tolyl (<b>b</b>); Ar1Ar2 = C₁₂H₈ (<b>c</b>)] were prepared by allowing chloro complexes RuCl­(η⁵-C₅Me₅)­(PPh₃)­[P­(OR)₃] to react with diazoalkane Ar1Ar2CN₂ in ethanol. The treatment of compounds <b>1</b> and <b>2</b> with H₂O afforded 1,2-diazene derivatives [Ru­(η⁵-C₅Me₅)­(η²-NHNH)­(PPh₃)­{P­(OR)₃}]­BPh₄ (<b>3</b> and <b>4</b>) and ketone Ar1Ar2CO. A reaction path involving nucleophilic attack by H₂O on the coordinated diazoalkane is proposed. The complexes were characterized spectroscopically (IR and NMR) and by X-ray crystal structure determination of [Ru­(η⁵-C₅Me₅)­(η²-NHNH)­(PPh₃)­{P­(OMe)₃}]­BPh₄ (<b>3</b>)