Unexpected Migratory Insertion Reactions of M(alkyl)2 (M=Zn,Cd) and Diamidocarbenes

The electrophilic character of free diamidocarbenes (DACs) allows them to activate inert bonds in small molecules, such as NH₃ and P₄. Herein, we report that metal coordinated DACs also exhibit electrophilic reactivity, undergoing attack by Zn and Cd dialkyl precursors to afford the migratory insertion products [(6‐MesDAC‐R)MR] (M=Zn, Cd; R=Et, Me; Mes=mesityl). These species were formed via the spectroscopically characterised intermediates [(6‐MesDAC)MR₂], exhibiting barriers to migratory insertion which increase in the order MR₂ = ZnEt₂ < ZnMe₂ < CdMe₂. Compound [(6‐MesDAC‐Me)CdMe] showed limited stability, undergoing deposition of Cd metal, by an apparent β‐H elimination pathway. These results raise doubts about the suitability of diamidocarbenes as ligands in catalytic reactions involving metal species bearing nucleophilic ligands (M‐R, M‐H).     

Zum Einfluß der Substituenten R = Ph,NEt2, iPr und tBu in Triphosphanen, (R2P)2P?SiMe3, und Phosphiden,Li(THF)2[(R2P)2P], auf die Bildung und Eigenschaften von Phosphinophosphiniden-Phosphoranen

Concerning the Influence of the Substituents R = Ph, NEt₂, ⁱPr, and ^tBu in Triphosphanes (R₂P)₂P? SiMe₃ and Phosphides Li(THF)₂[(R₂P)₂P] on the Formation and Properties of Phosphino-phosphinidene-phosphoranes The triphosphanes X₂P? P(SiMe₃)? PY₂ 5, 7, 9, 11, 13 and the derived phosphides Li(THF)₂[X₂P? P? PY₂] 6, 8, 10, 12, 14 were synthesized: 5 and 6 with X₂ = ⁱPr₂ and Y₂ = ^tBu₂, 7 and 8 with X₂ = Y₂ = Ph^tBu, 9 and 10 with X₂ = ^tBu₂ and Y₂ = Ph₂, 11 and 12 with X₂ = Y₂ = Ph₂, and 13 and 14 with X₂ = ^tBu₂ and Y₂ = (NEt₂)₂. The silylated triphosphanes at ?70°C in toluene with CBr₄ may yield X₂P? P?P(Br)Y₂ and X₂P? P(Br)? PY₂, and the lithiated phosphides with MeCl may yield X₂P? P?P(Me)Y₂ and X₂P? P(Me)? PY₂ depending on X and Y. The bromiated product of 5 (X₂ = ⁱPr₂, Y₂ = ^tBu₂) is the ylide ⁱPr₂P? P?P(Br)^tBu₂, and the methylated derivatives of 6 are both ⁱPr₂P? P?P(Me)^tBu₂, ^tBu₂P? P?P(Me)ⁱPr and the methylated triphosphane. Ph₂P? P?P(Br)^tBu₂ as well as the brominated triphosphane are obtained from 9 (X₂ = ^tBu₂, Y₂ = Ph₂), and similarly Ph₂P? P?P(Me)^tBu₂ and the methylated triphosphane from 10 . Compound 14 (X₂ = ^tBu₂, Y₂ = (NEt₂)₂ gives rise to the brominated ylide ^tBu₂)P? P?P(Br) · (NEt₂)₂ and to the brominated triphosphane, and on methylation to ^tBu₂P? P?P(Me)(NEt₂)₂ and to ^tBu₂P? P(Me)? P · (NEt₂)₂ (main product). The Br substituted derivatives decompose already on warming to ?30°C, while the methylated compounds are stable up to 20°C.     

Reactivity of [Mo(NHNRPh)(NNRPh)(acac)X2] (R=Ph,Me; X=Br,I) toward tertiary phosphines

The reactivity of mixed [organohydrazido(1-)][organohydrazido(2-)]molybdenum(VI) complexes [Mo(NHNRPh)(NNRPh)(acac)X₂] {R?=?Ph, X?=?Br (1); R?=?Ph, X?=?I (2) and R?=?Me; X?=?I (3)} with tertiary phosphines as PPh₃, PMePh₂ and PMe₂Ph are examined. The syntheses of [Mo(NNPh₂)₂Br₂(PPh₃)] (4), [Mo(NNPh₂)₂Br₂(PMePh₂)₂] (5), [Mo(NNPh₂)₂Br₂(PMe₂Ph)₂] (6), [Mo(NNPh₂)₂(acac)I(PPh₃)] (7), [Mo(NNPh₂)₂(acac)(PMePh₂)₂]⁺I^? (8) and [Mo(NNMePh)₂(acac)(PMePh₂)₂]⁺I^? (9) are reported. All complexes were characterized by elemental analysis, UV-visible, IR, ¹H and ³¹P{H} NMR spectroscopy.     

Five-, six- and eight-membered ring organosilicon chalcogenides of the types Z2(SiMe2)2E (Z = Me2Si, H2C; E = S, Se, Te), Z(SiMe2E)2MR2 (Z = Me2Si, H2C, O; E = S, Se, Te; M = Si, Ge, Sn, R = Me, Ph) and (SiMe2ZSiMe2E)2 (Z = Me2Si, H2C; E = S, Se)

Reactions of ClMe₂Si–Z–SiMe₂Cl (Z = SiMe₂ (1a), CH₂ (1c), O (1e)) with Li₂E (E = S, Se) yielded eight-membered ring compounds (SiMe₂ZSiMe₂E)₂ (3a–d) as well as acyclic oligomers (SiMe₂ZSiMe₂E)_x of different chain lengths. If 1:1 molar mixtures of 1a, 1c or 1e and a diorganodichlorosilane, -germane or -stannane (R₂MCl₂) are reacted with Li₂E (E = S, Se, Te), six-membered ring compounds Z(SiMe₂E)₂MR₂ (4a–7g) are formed exclusively. Five-membered rings Z₂(SiMe₂)₂E (Z = SiMe₂ (8a–c), CH₂ (9a–c); E = S, Se, Te) are obtained starting from the tetrasilane ClMe₂Si–(SiMe₂)₂–SiMe₂Cl (1b) or the disilylethane ClMe₂Si–(CH₂)₂–SiMe₂Cl (1d) by treatment with Li₂E. All products were characterized by multinuclear NMR spectroscopy (¹H, ¹³C, ²⁹Si, ¹¹⁹Sn, ⁷⁷Se, ¹²⁵Te, including coupling constants) and the effects of the different ring sizes towards NMR chemical shifts are discussed.     

Synthesis and Characterizations of Ti(O‐i‐Pr)Cl3(THF)(PhCOR) (R = H,Me, Ph) and Ti(O‐i‐Pr)Cl3(PhCOR)2 (R = Me,Ph). The Molecular Structure of Ti(O‐i‐Pr)Cl3(PhCOPh)2

A series of titanium(IV) complexes Ti(O‐i‐Pr)Cl₃(THF)(PhCOR) (R = H ( 1 ), CH₃ ( 2 ), or Ph ( 3 )) is prepared quantitatively from reactions of [Ti(O‐i‐Pr)Cl₂(THF)(μ‐Cl)]₂ with 2 molar equiv. PhCOR. Treatment of Ti(O‐i‐Pr)Cl₃ with 2 molar equiv. of PhCOR affords the disubstituted complexes Ti(O‐i‐Pr)Cl₃(PhCOR)₂ (R = CH₃ ( 4 ) or Ph ( 5 )). The ¹³C NMR study of these complexes shows that the relative bonding abilities are in the order of PhCOCH₃ > PhCHO > PhCOPh. The molecular structure of 5 reveals that one of the benzophenone ligands is trans to the strongest 2‐propoxide ligand with a long Ti‐O(carbonyl) distance of 2.193(5) Å which is much longer than the other Ti‐O(carbonyl) distance of 2.097(4) Å by ?0.1 Å. All ligands cis to the alkoxide ligand are bending away from the alkoxide ligand with the RO‐Ti‐L angles ranging from 93.6(2) to 99.0(2)°.     

[Cp2Ln(m-h1:h2-OC(SR)=CPh2 )]2 的合成和表征

[Cp2Ln（μ-SR）]2 was reacted with Ph2C=C=O to yield ketene mono-insertion products [Cp2Ln（μ-η1：η2-OC（SR）=CPh2）]2 [R=Bn, Ln=Yb （1）, Er （2）, Y （3） and R--Ph, Ln=Yb （4）], indicating that the reactions of organolanthanide thiolates with ketenes are independent of the nature of the thiolate ligand and the ketene as well as the reaction condition. These reactions could provide an efficient method for the synthesis of organolanthanide complexes with the a-thiolate-substituted enolate ligand. All these complexes were characterized by elemental analysis and spectroscopic properties and the structure of complex 1 was determined through X-ray single crystal diffraction analysis.     

类硅烯H2C＝SiLiBr与RH (R＝F, OH, NH2)的插入反应

采用DFT B3LYP和QCISD方法研究了类硅烯H2C＝SiLiBr与RH (R＝F, OH, NH2)的插入反应. 在B3LYP/6- 311＋G(d,p)水平上优化了反应势能面上的驻点构型. 结果表明, H2C＝SiLiBr与HF, H2O或NH3发生插入反应的机理相同. QCISD/6-311＋＋G(d,p)//B3LYP/6-311＋G(d,p)计算的三个反应的势垒分别为148.62, 164.42和165.07 kJ&#8226;mol－1, 反应热分别为－69.63, －43.02和－28.27 kJ&#8226;mol－1. 相同条件下发生插入反应时, 反应活性都是H—F＞H—OH＞H—NH2.     

类锗烯H2C=GeLiCl与RH(R=F,OH, NH2)的插入反应

采用DFT B3LYP和QCISD方法研究了不饱和类锗烯H2C=GeLiCl与RH(R=F, OH, NH2)的插入反应. 在B3LYP/6-311+G(d,p)水平上优化了反应势能面上的驻点构型. 结果表明, H2C=GeLiCl与HF、H2O 或NH3发生插入反应的机理相同. QCISD/6-311++G(d,p)//B3LYP/6-311+G(d,p)计算的三个反应的势垒分别为173.53、194.48和209.05 kJ·mol-1, 反应热分别为60.18、72.93和75.34 kJ·mol-1. 相同条件下发生插入反应时, 反应活性顺序都是H—F>H—OH>H—NH2.     

Synthese und Kristallstrukturen der Nitrido‐Chloro‐Molybdate [Mg(THF)4{NMoCl4(THF)}2] · 4 CH2Cl2 und [Li(12‐Krone‐4)(NMoCl4)]2 · 2 CH2Cl2

Syntheses and Crystal Structures of the Nitrido‐chloro‐molybdates [Mg(THF)₄{NMoCl₄(THF)}₂] · 4 CH₂Cl₂ and [Li(12‐Crown‐4)(NMoCl₄)]₂ · 2 CH₂Cl₂ Both the title compounds as well as [Li(12‐crown‐4)₂]⁺MoNCl₄^– were made from MoNCl₃ and the chlorides MgCl₂ and LiCl, respectively, in dichloromethane suspensions in the presence of tetrahydrofuran and 12‐crown‐4, respectively. They form orange‐red moisture‐sensitive crystals, which were characterized by their IR spectra and partly by crystal structure analyses. [Mg(THF)₄{NMoCl₄(THF)}₂] · 4 CH₂Cl₂ ( 1 ): space group C2/m, Z = 2, lattice dimensions at –50 °C: a = 1736.6(1), b = 1194.8(1), c = 1293.5(2) pm; β = 90.87(1)°; R₁ = 0.037. In 1 the magnesium ion is coordinated octahedrally by the oxygen atoms of the four THF molecules and in trans‐position by the nitrogen atoms of the two [N≡MoCl₄(THF)]^– ions. [Li(12‐crown‐4)(NMoCl₄)]₂ · 2 CH₂Cl₂ ( 2 ): space group P 1, Z = 1, lattice dimensions at –70 °C: a = 930.4(1), b = 957.9(1), c = 1264.6(1) pm; α = 68.91(1)°, β = 81.38(1)°, γ = 63.84(1)°; R₁ = 0.0643. 2 forms a centrosymmetric ion ensemble in the dimeric cation of which, i. e. [Li(12‐crown‐4)]₂²⁺, the lithium ions on the one hand are connected to the four oxygen atoms each of the crown ether molecules in a way not yet known; and in addition, each of the lithium ions enters into a intermolecular Li–O bond with neighboring crown ether molecules under formation of a Li₂O₂ four‐membered ring. The two N≡MoCl₄^– counterions are loosely coordinated to one oxygen atom each of the crown ether molecules with Mo–O distances of 320.2 pm.     

Stabilization of Classical [B2H5]−: Structure and Bonding of [(Cp*Ta)2(B2H5)(μ‐H)L2] (Cp*=η5‐C5Me5; L=SCH2S)

The room‐temperature reaction of [Cp*TaCl₄] with LiBH₄?THF followed by addition of S₂CPPh₃ results in pentahydridodiborate species [(Cp*Ta)₂(μ,η²:η²‐B₂H₅)(μ‐H)(κ²,μ‐S₂CH₂)₂] ( 1 ), a classical [B₂H₅]^? ion stabilized by the binuclear tantalum template. Theoretical studies and bonding analysis established that the unusual stability of [B₂H₅]^? in 1 is mainly due to the stabilization of sp²‐B center by electron donation from tantalum. Reactions to replace the hydrogens attached to the diborane moiety in 1 with a 2 e {M(CO)₄} fragment (M=Mo or W) resulted in simple adducts, [{(Cp*Ta)(CH₂S₂)}₂(B₂H₅)(H){M(CO)₃}] ( 6 : M=Mo and 7 : M=W), that retained the diborane(5) unit.     

Über den Phosphandiyl‐Transfer von invers‐polarisierten Phosphaalkenen R1P=C(NMe2)2 (R1 = tBu,Cy, Ph,H) auf Phospheniumkomplexe [(η5‐C5H5)(CO)2M=P(R2)R3] (R2 = R3 = Ph; R2 = tBu,R3 = H; R2 = Ph,R3 = N(SiMe3)2)

Phosphanediyl Transfer from Inversely Polarized Phosphaalkenes R¹P=C(NMe₂)₂ (R¹ = tBu, Cy, Ph, H) onto Phosphenium Complexes [(η⁵‐C₅H₅)(CO)₂M=P(R²)R³] (R² = R³ = Ph; R² = tBu, R³ = H; R² = Ph, R³ = N(SiMe₃)₂) Reaction of the freshly prepared phosphenium tungsten complex [(η⁵‐C₅H₅)(CO)₂W=PPh₂] ( 3 ) with the inversely polarized phosphaalkenes RP=C(NMe₂)₂ ( 1 ) ( a : R = tBu; b : Cy; c : Ph) led to the η²‐diphosphanyl complexes ( 9a‐c ) which were isolated by column chromatography as yellow crystals in 24‐30 % yield. Similarly, phosphenium complexes [(η⁵‐C₅H₅)(CO)₂M=P(H)tBu] (M = W ( 6 ); Mo ( 8 )) were converted into (M = W ( 11 ); Mo ( 12 )) by the formal abstraction of the phosphanediyl [PtBu] from 1a . Treatment of [(η⁵‐C₅H₅)(CO)₂W=P(Ph)N(SiMe₃)₂] ( 4 ) with HP=C(NMe₂)₂ ( 1d ) gave rise to the formation of yellow crystalline ( 10 ). The products were characterized by elemental analyses and spectra (IR, ¹H, ¹³C‐, ³¹P‐NMR, MS). The molecular structure of compound 10 was elucidated by an X‐ray diffraction analysis.     

Nitrocellulose Membrane,Modified by RC(S)NHP(X)(OiPr)2 (X = S,R = PhNH; X = O,R = PhNH,Ph), for Sorption Extraction of Cobalt Cations

The complexation and extraction properties of RC(S)NHP(X)(OiPr)₂ [X = S, R = PhNH (HL^I); X = O, R = PhNH (HL^II), Ph (HL^III)] towards cobalt cations were studied. The nitrocellulose membrane was used as a carrier for HL^I?III. The maximal degree of extraction of cobalt cations from an aqueous solution is observed at pH = 7.8–8.4. It was established that complexes formed are kept in a water solution on a surface of the carrier and washed away in 96% aqueous ethanol. The membrane modified by HL^I allows extraction and concentration of Co(II) selectively, while the modification by HL^III leads to the selective extraction of Co(III).     

{nBuMg(OR)}2 und {Mg(OR)2}2 (R = 2, 4, 6‐tBu3C6H2) – sterisch überfrachtete Magnesiumalkoholate

Reaction of 2, 4, 6‐tri‐tert‐butylphenol ( 1 ) with di‐n‐butylmagnesium in the molar ratio 1:1 allows the synthesis of {(nBu)Mg(μ‐OR)₂Mg(nBu)} ( 2 ) (R = 2, 4, 6‐tBu₃C₆H₂), which reacts with excess 1 to give the homoleptic alcoholate complex {(RO)Mg(μ‐OR)₂Mg(OR)} ( 3 ) (R = 2, 4, 6‐tBu₃C₆H₂). The structures of 2 and 3 were determined by X‐ray crystallography.     

The Reactions of Sodium Silanethiolates with Benzoyl Chloride. The Crystal Structures of (O‐silyl)thiobenzoates (tBuO)3SiOC(S)Ph,Ph3SiOC(S)Ph, (2,6‐XyO)3SiOC(S)Ph,and of PhC(O)SSSC(O)Ph

Benzoyl chloride reacts with sodium silanothiolates R₃SiSNa yielding exclusively silyl derivatives of thionobenzoic acid R₃SiOC(S)Ph, R = ^tBuO ( 1 ), R = Ph ( 2 ) and R = 2,6‐XyO ( 3 ) as orange solids. Compounds 1 , 2 , and 3 were fully characterized on the basis of X‐ray crystal structure analysis. NMR studies of solutions indicate that the same isomers are present in solutions and in solids.     

Lamellare Schichten auf der Grundlage von Wasserstoffbrücken und π‐Stapelung: Kristallstrukturen der Komplexe [Mg(H2O)6]Z2 und [Be(H2O)4]Z2�2 H2O mit Z‐ = C6H4(SO2)2N‐: Metallsalze des Benzol‐1, 2‐di(sulfonyl)amins. 8 [1, 2]

Metal Salts of Benzene‐1, 2‐di(sulfonyl)amine. 8. Lamellar Layers Based upon Hydrogen Bonding and π‐Stacking: Crystal Structures of the Complexes [Mg(H₂O)₆]Z₂ and [Be(H₂O)₄]Z₂�2 H₂O, where Z^‐ is C₆H₄(SO₂)₂N^‐ The crystal structures of the title complexes (both triclinic, space group P1¯, Z = 1 for M = Mg, Z = 2 for M = Be) have been determined by low‐temperature X‐ray diffraction. They consist of non‐coordinating ortho‐benzenedisulfonimide anions and, respectively, inversion‐symmetric octahedral [Mg(H₂O)₆]²⁺ cations or tetrahedral [Be(H₂O)₄]²⁺ cations and two non‐coordinating water molecules. In both structures, all O—H hydrogen bond donor groups are used to associate the components into two‐dimensional assemblies comprising an internal polar lamella of metal cations, (SO₂)₂N groups and water molecules, and hydrophobic peripheral regions consisting of vertically protruding benzo rings. Carbocycles drawn alternatingly from adjacent layers form π‐stacking arrays, whereby the aromatic rings display intercentroid distances in the range 340—370 pm. Several short C—H ⃜O contacts, which may be viewed as weak hydrogen bonds, occur within and between the layers.     

Photochemical Generation of Chiral N,B,X‐Heterocycles by Heteroaromatic C−X Bond Scission (X=S,O) and Boron Insertion

Chiral organoboron compounds with a chelate backbone and mesityl/heterocycle substituents (thienyl, furyl, and derivatives thereof) undergo a quantitative phototransformation that yields rare, chiral N,B,X‐containing heterocycles, such as base‐stabilized 1,2‐thiaborinines and 1,2‐oxaborinines. Boriranes were observed as intermediates in some of these transformations. The oxaborinines display further reactivity, generating 4a,12b‐dihydrobenzo[h][1,2]oxaborinino[4,3‐f]quinolines through a sequential conrotatory electrocyclization and a [1,5]‐H shift. The N,B,X‐containing heterocycles display strong blue‐green to orange‐red emission in the solid state. Combined DFT//CASP2T calculations suggest that a common biradical intermediate is responsible for the formation of these compounds as well as their interconversion.     

Rare‐Earth‐Rich Magnesium Compounds RE23Rh7Mg4 (RE = La,Ce, Pr,Nd, Sm,Gd) with Tetrahedral Mg4 Clusters

The rare earth‐rich compounds RE₂₃Rh₇Mg₄ (RE = La, Ce, Pr, Nd, Sm, Gd) were prepared by induction‐melting the elements in sealed tantalum tubes. The new compounds were characterized by X‐ray powder diffraction. They crystallize with the hexagonal Pr₂₃Ir₇Mg₄ type structure, space group P6₃mc. The structures of La₂₃Rh₇Mg₄ (a = 1019.1(1), c = 2303.7(4) pm, wR2 = 0.0827, 1979 F² values, 69 variables), Nd₂₃Rh₇Mg₄ (a = 995.4(2), c = 2242.3(5) pm, wR2 = 0.0592, 2555 F² values, 74 variables) and Gd₂₃Rh_6.86(5)Mg₄ (a = 980.5(2), c = 2205.9(5) pm, wR2 = 0.0390, 2083 F² values, 71 variables) were refined from single crystal X‐ray diffractometer data. The three crystallographically different rhodium atoms have trigonal prismatic rare earth coordination with short RE–Rh distances (283–300 pm in Nd₂₃Rh₇Mg₄). The prisms are condensed via common edges, leading to a rigid three‐dimensional network in which isolated Mg₄ tetrahedra (312–317 pm Mg–Mg in Nd₂₃Rh₇Mg₄) are embedded. Temperature dependent magnetic susceptibility data of Ce₂₃Rh₇Mg₄ indicate Curie‐Weiss behavior with an experimental magnetic moment of 2.52(1) μ_B/Ce atom, indicative for stable trivalent cerium. Antiferromagnetic ordering is evident at 2.9 K.     

(Ph2N)2Sm(THF)4与偶氮苯的反应：[(Ph2N)(DME)Sm]2(μ-η2:η2-N2Ph2)2的合成、X－光结构和催化行为

Reaction of divalent (Ph2N)2Sm(THF)4 with 1 equiv, of azobenzene in THF and then crystallization of the product in DME-Et2O mixed solvent produced the complex of [(PhEN)(DME)Sm]E(μ-η^2:η^2-N2Ph2)2 (1) in 65.0% yield. In complex 1, azobenzene molecules were reduced to be dianionic Ph2N2^2- ligands, bridging two samarium ions in two η^2:η^2 fashions. One samarium ion was bonded to a DME molecule and a diphenyl amido ligand besides two Ph2N2^2- ligands. The unusual Ln-η^2-arene close interaction was found for the first time for diphenyl amido lanthanides. Complex 1 could catalyze the polymerization of methyl methacrylate and acrylonitrile