Bis(cyclopentadienyl)methan-verbrückte Zweikernkomplexe. VIII. Zweikernige Cobaltkomplexe mit dem Dianion des Bis(cyclopentadienyl)methans und des Bis(tetramethylcyclopentadienyl)dimethylsilans als Brückenliganden

Bis(cyclopentadienyl)methane-bridged Dinuclear Complexes. VIII. Dinuclear Cobalt Complexes with the Dianion of Bis(cyclopentadienyl)methane and Bis(tetramethylcyclopentadienyl)dimethylsilane as Bridging Ligands The dinuclear cobalt complex [CH₂(C₅H₄)₂][Co(CO)₂]₂ ( 4 ) which is obtained from [Co(CO)₄I] ( 2 ) and Li₂[CH₂(C₅H₄)₂] ( 3 ) in 75% yield reacts with PMe₃, PiPr₃, P₂Me₄, Me₂PCH₂CH₂PMe₂ and (EtO)₂POP(OEt)₂, to the compounds 5–9 substituting one CO ligand per cobalt atom. Oxidative addition of CH₃I to [CH₂(C₅H₄)₂][Co(CO)(PMe₃)]₂ ( 5 ) leads to the formation of the dinuclear cobalt(III) complex [CH₂(C₅H₄)₂][Co(COCH₃)(PMe₃)I]₂ ( 11 ). The reaction of 4 with iodide generates [CH₂(C₅H₄)₂][Co(CO)I₂]₂ ( 12 ) which with PMe₃, P(OMe)₃, P(OiPr)₃, and CNMe reacts under CO substitution to [CH₂(C₅H₄)₂][Co(L)I₂]₂ ( 13–16 ) and with PMe₂H to {[CH₂(C₅H₄)₂][Co(PMe₂H)₃]₂}I₄ ( 17 ). The electrophilic addition reactions of NH₄PF₆ and CH₃I to [CH₂(C₅H₄)₂][Co(PMe₃)₂]₂ ( 20 ) produce the complex salts {[CH₂(C₅H₄)₂][CoR(PMe₃)₂]₂}X₂ ( 21 : R = H; 22 : R = CH₃). From 22a (X = I) and LiCH₃ the dinuclear tetramethyldicobalt compound [CH₂(C₅H₄)₂] · [Co(CH₃)₂(PMe₃)]₂ ( 23 ) is obtained which further reacts, via the intermediate 24 , to the chiral complex {[CH₂(C₅H₄)₂] · [CoCH₃(PMe₃)P(OMe)₃]₂}(PF₆)₂ ( 25 ). The reaction of 20 with C₂(CN)₄ and E- or Z-C₂H₂(CO₂Me)₂ gives the olefin(trimethylphosphine) cobalt(I) derivatives 26 und 27 . The synthesis of the dinuclear compounds 31–38 with [Me₂Si(C₅Me₄)₂]^2? as the bridging unit is also described.     

Synthesis and Characterization of β‐Diketiminate Aluminum Compounds and Their Use in the Ring‐Opening Polymerization of ε‐Caprolactone

Four aluminum alkyl compounds, [CH{(CH₃)CN‐2,4,6‐MeC₆H₂}₂AlMe₂] ( 1 ), [CH{(CH₃)CN‐2,4,6‐MeC₆H₂}₂AlEt₂] ( 2 ), [CH{(CH₃)CN‐2‐iPrC₆H₄}₂AlMe₂] ( 3 ), and [CH{(CH₃)CN‐2‐iPrC₆H₄}₂AlEt₂] ( 4 ), bearing β‐diketiminate ligands [CH{(Me)CN‐2,4,6‐MeC₆H₂}]₂ (L¹H) and [CH{(Me)CN‐2‐ⁱPrC₆H₄}]₂ (L²H) were obtained from the reactions of trimethylaluminum, triethylaluminum with the corresponding β‐diketiminate, respectively. All compounds were characterized by ¹H NMR and ¹³C NMR spectroscopy, single‐crystal X‐ray structural analysis, and elemental analysis. Compounds 1 – 4 were found to catalyze the ring‐opening polymerization (ROP) of ε‐caprolactone (ε‐CL) with good activity.     

[μ‐1κ2O,O′:2(η5)‐Cyclopentadienylcarboxylato][2(η5)‐diphenylphosphinocyclopentadienyl]bis[1,1(η5)‐tetramethylcyclopentadienyl]iron(II)titanium(III)

Reacting stoichiometric amounts of 1‐(diphenylphosphino)ferrocene­carboxylic acid and [Ti(η⁵‐C₅HMe₄)₂(η²‐Me₃SiC[triple‐bond]CSiMe₃)] produced the title carboxyl­atotitanocene complex, [{μ‐1κ²O,O′:2(η⁵)‐C₅H₄CO₂}{2(η⁵)‐C₅H₄P(C₆H₅)₂}{1(η⁵)‐C₅H(CH₃)₄}₂Fe^IITi^III] or [FeTi(C₉H₁₃)₂(C₆H₄O₂)(C₁₇H₁₄P)]. The angle subtended by the Ti/O/O′ plane, where O and O′ are the donor atoms of the κ²‐carboxy­late group, and the plane of the carboxyl‐substituted ferrocene cyclo­penta­dienyl is 24.93 (6)°.     

Basische metalle: LII. Synthese von carbenoid- und ylidcobalt(III)-komplexen aus substitutionslabilen cobalt(I)-vorstufen

The cyclopentadienylcobalt(I) compounds C₅H₅Co(PMe₃)P(OR)₃ (R = Me, Et, Prⁱ) and C₅H₅Co(C₂H₄)L (L = PMe₃, P(OMe)₃, CO) are prepared by ligand substitution starting from C₅H₅Co(PMe₃)₂ and C₅H₅Co(C₂H₄)₂. Whereas the reaction of C₅H₅Co(PMe₃)P(OMe)₃ with CH₂Br₂ mainly gives [C₅H₅CoBr(PMe₃)P(OMe)₃]Br, the dihalogenocobalt(III) complexes C₅H₅CoX₂(PMe₃) (X = Br, I) are obtained from C₅H₅Co(CO)PMe₃ and CH₂X₂. Treatment of C₅H₅Co(CO)PMe₃ or C₅H₅Co(C₂H₄)PMe₃ with CH₂ClI at low temperatures produces a mixture of C₅H₅CoCH₂Cl(PMe₃)I and C₅H₅CoCl(PMe₃)I, which can be separated due to their different solubilities. The same reaction in the presence of ligand L gives the carbenoidcobalt(III) compounds [C₅H₅CoCH₂Cl(PMe₃)L]PF₆ in nearly quantitative yields. If NEt₃ is used as the Lewis base, the ylide complexes [C₅H₅Co(CH₂PMe₃)(PMe₃)X]PF₆ (X = Br, I) are obtained. The PF₆ salts of the dications [C₅H₅Co(CH₂PMe₃)(PMe₃)L]²⁺ (L = PMe₃, P(OMe)₃, CNMe) and [C₅H₅Co(CH₂PMe₃)(P(OMe)₃)₂]²⁺ are prepared either from [C₅H₅Co(CH₂PMe₃)(PMe₃)X]⁺ and L, or more directly from C₅H₅Co(CO)PMe₃, CH₂X₂ and PMe₃ or P(OMe)₃, respectively. The synthesis of C₅H₅CoCH₂OMe(PMe₃)I is also described.     

Reactions of Cyclohexyl Isocyanide with η5‐Substituted Cyclo‐pentadienyl MoMo Triply Bonded Complexes. Crystal Structure of [Mo(CO)2(η5‐C5H4CO2CH3)]2(μ‐η2‐CNC6H11)

Reactions of one or two equiv. of cyclohexyl isocyanide in THF at room temperature with Mo?Mo triply bonded complexes [Mo(CO)₂(η⁵‐C₅H₄R)]₂ (R=COCH₃, CO₂CH₃) gave the isocyanide coordinated Mo? Mo singly bonded complexes with functionally substituted cyclopentadienyl ligands, [Mo(CO)₂(η⁵‐C₅H₄R)]₂(μ‐η²‐CNC₆H₁₁) ( 1a , R=COCH₃; 1b , R=CO₂CH₃) and [Mo(CO)₂(η⁵‐C₅H₄R)(CNC₆H₁₁)]₂ ( 2a , R=COCH₃; 2b , R=CO₂CH₃), respectively. Complexes 1a , 1b and 2a , 2b could be more conveniently prepared by thermal decarbonylation of Mo? Mo singly bonded complexes [Mo(CO)₃(η⁵‐C₅H₄R)]₂ (R=COCH₃, CO₂CH₃) in toluene at reflux, followed by treatment of the resulting Mo?Mo triply bonded complexes [Mo(CO)₂(η⁵‐C₅H₄R)]₂ (R=COCH₃, CO₂CH₃) in situ with cyclohexyl isocyanide. While 1a , 1b and 2a , 2b were characterized by elemental analysis and spectroscopy, 1b was further characterized by X‐ray crystallography.     

Chloridobis[2‐(diphenylphosphanyl)ethanamine‐κ2P,N](triphenylphosphane‐κP)ruthenium(II) chloride toluene monosolvate

The aminophosphane ligand 1‐amino‐2‐(diphenylphosphanyl)ethane [Ph₂P(CH₂)₂NH₂] reacts with dichloridotris(triphenylphosphane)ruthenium(II), [RuCl₂(PPh₃)₃], to form chloridobis[2‐(diphenylphosphanyl)ethanamine‐κ²P,N](triphenylphosphane‐κP)ruthenium(II) chloride toluene monosolvate, [RuCl(C₁₈H₁₅P)(C₁₄H₁₆NP)₂]Cl·C₇H₈ or [RuCl(PPh₃){Ph₂P(CH₂)₂NH₂}₂]Cl·C₇H₈. The asymmetric unit of the monoclinic unit cell contains two molecules of the Ru^II cation, two chloride anions and two toluene molecules. The Ru^II cation is octahedrally coordinated by two chelating Ph₂P(CH₂)₂NH₂ ligands, a triphenylphosphane (PPh₃) ligand and a chloride ligand. The three P atoms are meridionally coordinated, with the Ph₂P– groups from the ligands being trans. The two –NH₂ groups are cis, as are the chloride and PPh₃ ligands. This chiral stereochemistry of the [RuCl(PPh₃){Ph₂P(CH₂)₂NH₂}₂]⁺ cation is unique in ruthenium–aminophosphane chemistry.     

Sodium tris(acetato‐κ2O,O′)dioxidoamericate(VI) and guanidinium tris(cyclopropanecarboxylato‐κ2O,O′)dioxidoamericate(VI)

The title compounds, Na[{AmO₂}(C₂H₃O₂)₃], (I), and (CH₆N₃)[{AmO₂}(C₄H₅O₂)₃], (II), contain complex anions in which AmO₂²⁺ cations are surrounded by three bidentate‐chelating carboxylate groups. The atoms of the AmO₂ group and the Na atoms in (I) are situated on threefold axes. All the atoms in (II) occupy general positions. Both compounds are isomorphous with earlier studied analogous compounds of previous members of the actinide (An) series.     

Synthesen zweizähniger P‐Donor/Sn‐Akzeptor‐Liganden: Koordinationsstudien mit Cp*Rh(CO)2 und CpRh(C2H4)2

Alternative Ligands. XXXV. Syntheses of Bidentate P‐Donor/Sn‐Acceptor Ligands: Coordination Experiments with Cp*Rh(CO)₂ and CpRh(C₂H₄)₂ Donor/acceptor ligands Me₂Sn(CH₂CH₂PMe₂)₂ ( 1 ) and Me₂Sn(OCH₂PMe₂)₂ ( 2 ) have been prepared by radical reaction of Me₂PVi with Me₂SnH₂ and by substitution of chlorine in Me₂SnCl₂ or of ethoxy groups in Me₂Sn(OEt)₂ by MOCH₂PMe₂ (M = Li, Na) and HOCH₂PMe₂, respectively. 2 cannot be isolated in pure form from the product mixture because, due to condensation reactions, the “ladder structure” [Me₂Sn(OCH₂PMe₂)₂OSnMe₂]₂ ( 3 ) is formed. The molecular structure of 3 was determined by X‐ray diffraction studies of single crystals. Attempts to produce the thiophosphoryl derivative of 3 result in the degradation of the ladder structure giving the thermally labile phosphane sulfide Me₂Sn(OCH₂P(S)Me₂)₂. Ligands 1 and 2 besides Me₂PCH₂CH₂SnMe₃ ( 4 ) have been used for the preparation of rhodium(I) complexes from Cp*Rh(CO)₂ ( 5 ) or CpRh(C₂H₄)₂ ( 10 ) as educts. The thermal reaction of 5 with 4 yields Cp*Rh(CO)PMe₂CH₂CH₂SnMe₃ ( 6 ), that of 5 with 1 a mixture of the mononuclear derivative Cp*Rh(CO) · PMe₂CH₂CH₂SnMe₂CH₂CH₂PMe₂ ( 7 ) and the binuclear complex [Cp*Rh(CO)PMe₂CH₂CH₂]₂SnMe₂ ( 8 ). The related system [Cp*Rh(CO)PMe₂CH₂O]₂SnMe₂ produced by reaction of 5 with 2 can only be detected in solution but, because of some side‐products, was not fully characterized. From 10 and 4 a mixture of mono‐ and disubstituted products, CpRh(C₂H₄)PMe₂CH₂CH₂SnMe₃ ( 11 ) and CpRh(PMe₂CH₂CH₂SnMe₃)₂ ( 12 ), is obtained. Reaction of 1 with 10 yields a mixture of the complexes CpRh(C₂H₄)PMe₂CH₂CH₂SnMe₂CH₂CH₂PMe₂ ( 13 ) and CpRh(Me₂CH₂CH₂)₂SnMe₂ ( 14 ). Some of the NMR data (¹³C, δδ_Sn) of 14 can be interpreted in terms of the expected Rh → Sn interaction. A definite proof by X‐ray diffraction on single crystals, so far, was not possible.     

[Co(g5‐Me5C5)(g3‐tBu2PPCH–CH3)] aus [Co(g5‐Me5C5)(g2‐C2H4)2] und tBu2P–P=P(Me)tBu2

Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes. XVII [1] [Co(g⁵‐Me₅C₅)(g³‐^tBu₂PPCH–CH₃)] from [Co(g⁵‐Me₅C₅)(g²‐C₂H₄)₂] and ^tBu₂P–P=P(Me)^tBu₂ [Co(η⁵‐Me₅C₅)(η³‐^tBu₂PPCH–CH₃)] 1 is formed in the reaction of [Co(η⁵‐Me₅C₅)(η²‐C₂H₄)₂] 2 with ^tBu₂P–P 4 (generated from ^tBu₂P–P=P(Me)^tBu₂ 3 ) by elimination of one C₂H₄ ligand and coupling of the phosphinophosphinidene with the second one. The structure of 1 is proven by ³¹P, ¹³C, ¹H NMR spectra and the X‐ray structure analysis. Within the ligand ^tBu₂P¹P²C¹H–CH₃ in 1 , the angle P1–P2–C1 amounts to 90°. The Co, P1, P2, C1 atoms in 1 look like a „butterfly”︁. The reaction of 2 with a mixture of ^tBu₂P–P=P(Me)^tBu₂ 3 and ^tBu–C?P 5 yields [Co(η⁵‐Me₅C₅){η⁴‐(^tBuCP)₂}] 6 and 1 . While 6 is spontaneously formed, 1 appears only after complete consumption of 5 .     

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.     

2J(P,C) and 3J(P,C) Coupling Constants in Some New Phosphoramidates. Crystal Structures of CF3C(O)N(H)P(O)[N(CH3)(CH2C6H5)]2 and 4‐NO2‐C6H4N(H)P(O)[4‐CH3‐NC5H9]2

Some new phosphoramidates were synthesized and characterized by ¹H, ¹³C, ³¹P NMR, IR spectroscopy and elemental analysis. The structures of CF₃C(O)N(H)P(O)[N(CH₃)(CH₂C₆H₅)]₂ ( 1 ) and 4‐NO₂‐C₆H₄N(H)P(O)[4‐CH₃‐NC₅H₉]₂ ( 6 ) were confirmed by X‐ray single crystal determination. Compound 1 forms a centrosymmetric dimer and compound 6 forms a polymeric zigzag chain, both via ‐N‐H…O=P‐ intermolecular hydrogen bonds. Also, weak C‐H…F and C‐H…O hydrogen bonds were observed in compounds 1 and 6 , respectively. ¹³C NMR spectra were used for study of ²J(P,C) and ³J(P,C) coupling constants that were showed in the molecules containing N(C₂H₅)₂ and N(C₂H₅)(CH₂C₆H₅) moieties, ²J(P,C)>³J(P,C). A contrast result was obtained for the compounds involving a five‐membered ring aliphatic amine group, NC₄H₈. ²J(P,C) for N(C₂H₅)₂ moiety and in NC₄H₈ are nearly the same, but ³J(P, C) values are larger than those in molecules with a pyrrolidinyl ring. This comparison was done for compounds with six and seven‐membered ring amine groups. In compounds with formula XP(O)[N(CH₂R)(CH₂C₆H₅)]₂, ²J(P,CH₂)_benzylic>²J(P,CH₂)_aliphatic, in an agreement with our previous study.     

Isomorphous rare‐earth tris[bis(2,6‐diisopropylphenyl) phosphate] complexes and their catalytic properties in 1,3‐diene polymerization and in the inhibited oxidation of polydimethylsiloxane

Crystals of mononuclear tris[bis(2,6‐diisopropylphenyl) phosphato‐κO]pentakis(methanol‐κO)lanthanide methanol monosolvates of lanthanum, [La(C₂₄H₃₄O₄P)₃(CH₃OH)₅]·CH₃OH, ( 1 ), cerium, [Ce(C₂₄H₃₄O₄P)₃(CH₃OH)₅]·CH₃OH, ( 2 ), and neodymium, [Nd(C₂₄H₃₄O₄P)₃(CH₃OH)₅]·CH₃OH, ( 3 ), have been obtained by reactions between LnCl₃(H₂O)_n (n = 6 or 7) and lithium bis(2,6‐diisopropylphenyl) phosphate in a 1:3 molar ratio in methanol media. Compounds ( 1 )–( 3 ) crystallize in the monoclinic P2₁/c space group and have isomorphous crystal structures. All three bis(2,6‐diisopropylphenyl) phosphate ligands display a κO‐monodentate coordination mode. The coordination number of the metal atom is 8. Each [Ln{O₂P(O‐2,6‐ⁱPr₂C₆H₃)₂}₃(CH₃OH)₅] molecular unit exhibits four intramolecular O—H…O hydrogen bonds, forming six‐membered rings. The unit forms two intermolecular O—H…O hydrogen bonds with one noncoordinating methanol molecule. All six hydroxy H atoms are involved in hydrogen bonding within the [Ln{O₂P(O‐2,6‐ⁱPr₂C₆H₃)₂}₃(CH₃OH)₅]·CH₃OH unit. This, along with the high steric hindrance induced by the three bulky diaryl phosphate ligands, prevents the formation of a hydrogen‐bond network. Complexes ( 1 )–( 3 ) exhibit disorder of two of the isopropyl groups of the phosphate ligands. The cerium compound ( 2 ) demonstrates an essential catalytic inhibition in the thermal decomposition of polydimethylsiloxane in air at 573 K. Catalytic systems based on the neodymium complex tris[bis(2,6‐diisopropylphenyl) phosphato‐κO]neodymium, ( 3′ ), which was obtained as a dry powder of ( 3 ) upon removal of methanol, display a high catalytic activity in isoprene and butadiene polymerization.     

Polymorph of {2‐[(2‐hydroxyethyl)iminiomethyl]phenolato‐κO}dioxido{2‐[(2‐oxidoethyl)iminomethyl]phenolato‐κ3O,N,O′}molybdenum(VI)

A second polymorphic form (form I) of the previously reported compound {2‐[(2‐hydroxyethyl)iminiomethyl]phenolato‐κO}dioxido{2‐[(2‐oxidoethyl)iminomethyl]phenolato‐κ³O,N,O′}molybdenum(VI) (form II), [Mo(C₉H₉NO₂)O₂(C₉H₁₁NO₂)], is presented. The title structure differs from the previously reported polymorph [Głowiak, Jerzykiewicz, Sobczak & Ziółkowski (2003). Inorg. Chim. Acta, 356 , 387–392] by the fact that the asymmetric unit contains three molecules linked by O—H...O hydrogen bonds. These trimeric units are further linked through O—H...O hydrogen bonds to form a chain parallel to the [11] direction. As in the previous polymorph, each molecule is built up from an MoO₂²⁺ cation surrounded by an O,N,O′‐tridentate ligand (O⁻C₆H₄CH=NCH₂CH₂O⁻) and weakly coordinated by a second zwitterionic ligand (O⁻C₆H₄CH=N⁺HC₂H₄OH). All complexes are chiral with the absolute configuration at Mo being C or A. The main difference between the two polymorphs results from the alternation of the chirality at Mo within the chain.     

Counter‐anion role in the formation of two supramolecular complexes: [Ag2(DPP)2](ClO4)2·CH3CN and [Ag2(DPP)2(NO3)2] {DPP is N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine}

The title compounds, bis{μ‐N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine‐κ²N¹:P}disilver bis(perchlorate) acetonitrile monosolvate, [Ag₂(C₁₈H₁₇N₂P)₂](ClO₄)₂·CH₃CN, (1), and bis{μ‐N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine‐κ²N¹:P}bis[(nitrato‐κ²O,O)silver], [Ag₂(C₁₈H₁₇N₂P)₂(NO₃)₂], (2), each contain disilver macrocyclic [Ag₂(C₁₈H₁₇N₂P)₂]²⁺ cations lying about inversion centres. The cations are constructed by two N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine (DPP) ligands linking two Ag⁺ cations in a head‐to‐tail fashion. In (1), the unique Ag⁺ cation has a near‐linear coordination geometry consisting of one pyridine N atom and one P atom from two different DPP ligands. Two ClO₄⁻ anions doubly bridge two metallomacrocycles through Ag...O and N—H...O weak interactions to form a chain extending in the c direction. The half‐occupancy acetonitrile molecule lies with its methyl C atom on a twofold axis and makes a weak N...Ag contact. In (2), there are two independent [Ag(C₁₈H₁₇N₂P)]⁺ cations. The nitrate anions weakly chelate to each Ag⁺ cation, leading to each Ag⁺ cation having a distorted tetrahedral coordination geometry consisting of one pyridine N atom and one P atom from two different DPP ligands, and two chelating nitrate O atoms. Each dinuclear [Ag₂(C₁₈H₁₇N₂P)₂(NO₃)₂] molecule acts as a four‐node to bridge four adjacent equivalent molecules through N—H...O interactions, forming a two‐dimensional sheet parallel to the bc plane. Each sheet contains dinuclear molecules involving just Ag1 or Ag2 and these two types of sheet are stacked in an alternating fashion. The sheets containing Ag1 all lie near x = , , etc, while those containing Ag2 all lie near x = 0, 1, 2 etc. Thus, the two independent sheets are arranged in an alternating sequence at x = 0, , 1, etc. These two different supramolecular structures result from the different geometric conformations of the templating anions which direct the self‐assembly of the cations and anions.     

Synthesis and characterization of aluminum(III) and tin(II) complexes supported by diiminophosphinate ligands and their application in ring‐opening polymerization catalysis of ε‐caprolactone

A series of Al(III) and Sn(II) diiminophosphinate complexes have been synthesized. Reaction of Ph(ArCH₂)P(?NBu^t)NHBu^t (Ar = Ph, 3 ; Ar = 8‐quinolyl, 4 ) with AlR₃ (R = Me, Et) gave aluminum complexes [R₂Al{(NBu^t)₂P(Ph)(CH₂Ar)}] (R = Me, Ar = Ph, 5 ; R = Me, Ar = 8‐quinolyl, 6 ; R = Et, Ar = Ph, 7 ; R = Et, Ar = quinolyl, 8 ). Lithiated 3 and 4 were treated with SnCl₂ to afford tin(II) complexes [ClSn{(NBu^t)₂P(Ph)(CH₂Ar)}] (Ar = Ph, 9 ; Ar = 8‐quinolyl, 10 ). Complex 9 was converted to [(Me₃Si)₂NSn{(NBu^t)₂P(Ph)(CH₂Ph)}] ( 11 ) by treatment with LiN(SiMe₃)₂. Complex 11 was also obtained by reaction of 3 with [Sn{N(SiMe₃)₂}₂]. Complex 9 reacted with [LiOC₆H₄Bu^t‐4] to yield [4‐Bu^tC₆H₄OSn{(NBu^t)₂P(Ph)(CH₂Ph)}] ( 12 ). Compounds 3–12 were characterized by NMR spectroscopy and elemental analysis. The structures of complexes 6 , 10 , and 11 were further characterized by single crystal X‐ray diffraction techniques. The catalytic activity of complexes 5–8 , 11 , and 12 toward the ring‐opening polymerization of ε‐caprolactone (CL) was studied. In the presence of BzOH, the complexes catalyzed the ring‐opening polymerization of ε‐CL in the activity order of 5 > 7 ≈ 8 > 6 ? 11 > 12 , giving polymers with narrow molecular weight distributions. The kinetic studies showed a first‐order dependency on the monomer concentration in each case. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4621–4631, 2006     

Photocontrolled Living Anionic Polymerization of Phosphorus‐Bridged [1]Ferrocenophanes: A Route to Well‐Defined Polyferrocenylphosphine (PFP) Homopolymers and Block Copolymers

Phosphorus‐bridged strained [1]ferrocenophanes [Fe{(η‐C₅H₄)₂P(CH₂CMe₃)}] ( 2 ) and [Fe{(η‐C₅H₄)₂P(CH₂SiMe₃)}] ( 3 ) with neopentyl and (trimethylsilyl)methyl substituents on phosphorus, respectively, have been synthesized and characterized. Photocontrolled living anionic ring‐opening polymerization (ROP) of the known phosphorus‐bridged [1]ferrocenophane [Fe{(η‐C₅H₄)₂P(CMe₃)}] ( 1 ) and the new monomers 2 and 3 , initiated by Na[C₅H₅] in THF at 5 °C, yielded well‐defined polyferrocenylphosphines (PFPs), [Fe{(η‐C₅H₄)₂PR}]_n (R=CMe₃ ( 4 ), CH₂CMe₃ ( 5 ), and CH₂SiMe₃ ( 6 )), with controlled molecular weights (up to ca. 60×10³ Da) and narrow molecular weight distributions. The PFPs 4 – 6 were characterized by multinuclear NMR spectroscopy, DSC, and by GPC analysis of the corresponding poly(ferrocenylphosphine sulfides) obtained by sulfurization of the phosphorus(III) centers. The living nature of the photocontrolled anionic ROP allowed the synthesis of well‐defined all‐organometallic PFP‐b‐PFS_F ( 7 a and 7 b ) (PFS_F=polyferrocenylmethyl(3,3,3,‐trifluoropropyl)silane) diblock copolymers through sequential monomer addition. TEM studies of the thin films of the diblock copolymer 7 b showed microphase separation to form cylindrical PFS_F domains in a PFP matrix.     

Synthesis and selected reactions of pentakis ( t -octylisocyanide)cobalt(II) complexes

The ligand 1,1,3,3-tetramethylbutylisocyanide, CNCMe₂CH₂CMe₃, i.e. t-octylisocyanide, with Co(ClO₄)₂ · 6H₂O or Co(BF₄)₂ · 6H₂O in ethanol, produces pentakis(alkylisocyanide)cobalt(II) complexes, [Co(CNC₈H₁₇-t)₅](ClO₄)₂ (1) and [Co(CNC₈H₁₇-t)₅](BF₄)₂ · 2.0H₂O (2). These Co(II) complexes undergo reduction/substitution upon reaction with trialkylphosphine ligands to produce [Co(CNC₈H₁₇-t)₃{P(C₄H₉-n)₃}₂]ClO₄ (3), [Co(CNC₈H₁₇-t)₃{P(C₄H₉-n)₃}₂]BF₄ (4), and [Co(CNC₈H₁₇-t)₃{P(C₃H₇-n)₃}₂]ClO₄ (5). Complex 3 is oxidized with AgClO₄ to produce [Co(CNC₈H₁₇-t)₃{P(C₄H₉-n)₃}₂](ClO₄)₂ (6). Complex 1 yields [Co(CNC₈H₁₇-t)₄py₂](ClO₄)₂ (7) upon dissolving in pyridine. Reactions with triarylphosphine and triphenylarsine ligands were unsatisfactory. The chemistry of 1 and 2 is therefore more similar to that of Co(II) complexes with CNCMe₃ than with CNCHMe₂, other alkylisocyanides, or arylisocyanides, but shows some behavior dissimilar to any known Co(II) complexes of alkylisocyanides or arylisocyanides. Infrared and electronic spectra, magnetic susceptibility, molar conductivities, and cyclic voltammetry are reported and compared with known complexes. ¹H, ¹³C, and ³¹P NMR data were also measured for the diamagnetic complexes 3, 4, and 5.     

Zur Umsetzung von Kupfer(I)‐ und Kupfer(II)‐Salzen mit P(C6H4CH2NMe2‐2)3 ‐ die Festkörperstrukturen von {[P(C6H4CH2NMe2‐2)3]CuOClO3}ClO4, {[P(C6H4CH2NMe2‐2)3]Cu}ClO4, [P(C6H4CH2NMe2‐2)3]CuONO2 und [P(C6H4CH2NMe2‐2)2(C6H4CH2NMe2H+NO3‐‐2)]CuONO2

Reaction Behaviour of Copper(I) and Copper(II) Salts Towards P(C₆H₄CH₂NMe₂‐2)₃ ‐ the Solid‐State Structures of {[P(C₆H₄CH₂NMe₂‐2)₃]CuOClO₃}ClO₄, {[P(C₆H₄CH₂NMe₂‐2)₃]Cu}ClO₄, [P(C₆H₄CH₂NMe₂‐2)₃]CuONO₂ and [P(C₆H₄CH₂NMe₂‐2)₂(C₆H₄CH₂NMe₂H⁺NO₃^‐‐2)]CuONO₂ The reaction behaviour of P(C₆H₄CH₂NMe₂‐2)₃ ( 1 ) towards different copper(II) and copper(I) salts of the type CuX₂ ( 2a : X = BF₄, 2b : X = PF₆, 2c : X = ClO₄, 2d : X = NO₃, 2e : X = Cl, 2f : X = Br, 13 : X = O₂CMe) and CuX ( 5a : X = ClO₄, 5b : X = NO₃, 5c : X = Cl, 5d : X = Br) is discussed. Depending on X, the transition metal complexes [P(C₆H₄CH₂NMe₂‐2)₃Cu]X₂ ( 3a : X = BF₄, 3b : X = PF₆), {[P(C₆H₄CH₂NMe₂‐2)₃]CuX}X ( 4 : X = ClO₄, 11a : X = Cl, 11b : X = Br, 14 : X = O₂CMe), {[P(C₆H₄CH₂NMe₂‐2)₃]Cu}ClO₄ ( 6 ), [P(C₆H₄CH₂NMe₂‐2)₃]CuX ( 7a : X = Cl, 7b : X = Br, 10 : X = ONO₂), [P(C₆H₄CH₂NMe₂‐2)₂(C₆H₄CH₂NMe₂H⁺NO₃^‐‐2)]CuONO₂ ( 9 ) and [P(C₆H₄CH₂NMe₂‐2)₃]CuCl}CuCl₂ ( 12 ) are accessible. While in 3a , 3b and 6 the phosphane 1 preferentially acts as tetrapodale ligand, in all other species only the phosphorus atom and two of the three C₆H₄CH₂NMe₂ side‐arms are datively‐bound to the appropriate copper ion. In solution a dynamic behaviour of the latter species is observed. Due to the coordination ability of X in 3a , 3b and 6 non‐coordinating anions X^‐ are present. However, in 4 one of the two perchlorate ions forms a dative oxygen‐copper bond and the second perchlorate ion acts as counter ion to {[P(C₆H₄CH₂NMe₂‐2)₃]CuOClO₃}⁺. In 7 , 9 and 10 the fragments X (X = Cl, Br, ONO₂) form a σ‐bond with the copper(I) ion. The acetate moiety in 14 acts as chelating ligand as it could be shown by IR‐spectroscopic studies. All newly synthesised cationic and neutral copper(I) and copper(II) complexes are representing stable species. Redox processes are involved in the formation of 9 and 12 by reacting 1 with 2 . The solid‐state structures of 4 , 6 , 9 and 10 are reported. In the latter complexes the copper(II) ( 4 ) or copper(I) ion ( 6 , 9 , 10 ) possesses the coordination number 4. This is achieved by the formation of a phosphorus‐ and two nitrogen‐copper‐ ( 4 , 9 , 10 ) or three ( 6 ) nitrogen‐copper dative bonds and a coordinating ( 4 ) or σ‐binding ( 9 , 10 ) ligand X. In 6 all three nitrogen and the phosphorus atoms are coordinatively bound to copper, while X acts as non‐coordinating counter‐ion. Based on this, the respective copper ion occupies a distorted tetrahedral coordination sphere. While in 4 and 10 a free, neutral Me₂NCH₂ side‐arm is present, which rapidly exchanges in solution with the coordinatively‐bound Me₂NCH₂ fragments, this unit is protonated in 10 . NO₃^‐ acts as counter ion to the CH₂NMe₂H⁺ moiety. In all structural characterized complexes 6‐membered boat‐like CuPNC₃ cycles are present.     

C‐O Bond Cleavage of Diethyl Ether and Tetrahydrofurane by [(dpp‐BIAN)AlI(Et2O)] [dpp‐BIAN = 1,2‐bis[(2,6‐di‐iso‐propylphenyl)‐imino]acenaphthene]

At elevated temperatures, the aluminum complex [(dpp‐BIAN)AlI(Et₂O)] ( 1 ) splits the C‐O bonds of diethyl ether and tetrahydrofurane yielding the dimeric alkoxides [(dpp‐BIAN)AlOEt]₂ ( 2 ) and [(dpp‐BIAN)AlO(CH₂)₄I]₂ ( 3 ), respectively. Already at ambient temperatures, a cleavage of the C‐O bond of THF is to observe in the reaction of 1 with CpNa in THF as confirmed by the formation of [(dpp‐BIAN)AlO(CH₂)₄C₅H₅]₂ ( 4a ) and [(dpp‐BIAN)Al{O(CH₂)₄C₅H₅}(THF)] ( 4b ) in a molar ratio of 1:2. The reaction of 1 with t‐BuOK affords the monomeric alkoxide [(dpp‐BIAN)AlO‐t‐Bu(Et₂O)] ( 5 ). Compounds 2 , 3 , and 4a/b were characterized by elemental analyses and IR spectra. Additionally, the structures of 2 and 3 were determined by single crystal X‐ray diffraction.     

{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.