摘要:

Metal Complexes with Tetrapyrrole Ligands, LIX. – Redox Potentials, Near‐Infrared Absorption, Ionic Radii, and Ring‐Ring Distance in Metal(III) Bis(tetraphenylporphyrinate) Systems with Porphyrin Rings in Different Oxidation StatesAn extended series of tetrabutylammonium salts of bisporphyrinate double decker anions NBu4[MIII(TPP)2] (M = Y, La – Lu except Pm) is described. The complexes are characterized by UV/Vis/NIR and1H‐NMR spectroscopy, cyclic voltammetry, and spectroelectrochemistry. The redox potentials of the new sandwich compounds and the near‐infrared absorption energies of their corresponding oxidation products M(TPP)2and [M(TPP)2]+are shown to depend linearly on the ionic radii of the central ions. The gradients of the first and second oxidation potentials are positive whereas those of the third and fourth oxidation potentials are negative. This result is interpreted by means of a qualitative molecular orbital diagram describing the ππ interactions of the four frontier orbitals of the two macrocycles in the double dec

ISSN:0009-2940    

DOI:10.1002/cber.19911241002

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Thiolato Complexes of Monovalent Gold. Synthesis and Structure of [(2,4,6‐iPr3C6H2S)Au]6and (NH4)[(2,4,6‐iPr3C6H2S)2Au]Reaction of Au(CO)Cl with 2,4,6‐tri(isopropyl)thiophenol affords hexameric gold(I) thiolate [(2,4,6‐iPr3C6H2S)Au]6(1). According to an X‐ray analysis1forms a centrosymmetrical twelve‐membered Au – S ring in the chair conformation with the linearly coordinated Au atoms at the mid‐edges and the S atoms at the corners of the heterocycle. When the reaction of 2,4,6‐tri(isopropyl)thiophenol is carried out with AuI in liquid ammonia the thiolato complex [(2,4,6‐iPr3C6H2S)2Au]–‐NH+4(2) is obtained. It crystallizes as NH4·2·3NH3. The gold atom in2is linearly coordinated by two thiolato S atoms. The ammonium cation forms hydrogen bonds with t

ISSN:0009-2940    

DOI:10.1002/cber.19911241003

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Metallacyclobutenes via η2‐Cyclopropene Complexes of Titanocene and Zirconocene(η2‐Cyclopropene)(trimethylposphane) complexes of titanocene (4,5) and zirconocene (8) are obtained in good yields by the reaction of 1,2‐diphenylcyclopropene (2) or 4,8‐dioxaspiro[2.5]oct‐1‐ene (3) with bis(trimethylphosphane)titanocene (1) and (1‐butene)(trimethylphosphane)zirconocene (7), respectively. In solution the new complexes4and8rearrange smoothly above room temperature to give the metallacyclobutene derivatives6and9. All new compounds were characterized by spectroscopic methods (31P,1H,13C NMR), and the crystal structure of9was determined by an

ISSN:0009-2940    

DOI:10.1002/cber.19911241004

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Metal‐Containing Heterocycles: Preparation, Properties, Reactions, LXXVII. – Synthesis, Structure and Reactivity of Phosphametallacyclopropanes with Isolobal ER (E = N,P,As,Sb) and Fe(CO)4Building BlocksThe phosphidometallates\documentclass{article}\usepackage{amsmath}\pagestyle{empty}\begin{document}$ Li_2 \left\{ {\left[ M \right]\dddot - PPh_2 } \right\} $\end{document}{[M] = (η5‐C5H5)M‐(CO)2}, resulting from the metal hydride complexes H[M]PPh2H [M = Cr (1), Mo (2), W (3)] by reduction withnBuLi, react with the geminal dihalides RECl2to give the three‐membered phosphametallacyclopropanes [ER = NC6F5(M = Cr (1a), Mo (2a), W (3a)), PPh (M = Cr (1b), Mo (2b), W (3b)), PC6H11(M = Cr (1c), Mo (2c), W (3c)), P‐tBu (M = Cr (1d), Mo (2d), W (3d)), P(2,4,6‐(tBu)3C6H2) (M = Cr (1e), Mo (2e), W (3e)), As(2,4,6‐(tBu)3C6H2) (M = Cr (1f), Mo (2f), W (3f)), Sb‐tBu (M = Cr (1g), Mo (2g))]. Reaction of Br2Fe(CO)4with the corresponding dilithium compounds\documentclass{article}\usepackage{amsmath}\pagestyle{empty}\begin{document}$ Li_2 \left\{ {\left[ M \right]\dddot - PPh_2 } \right\} $\end{document}affords the phosphido‐bridged heterodimetallic complexes . According to X‐ray structural analyses in2aand2fthe P – E bond distances are shortened while the Mo – E bonds are significantly elongated compared to a single bond. (OC)5CrTHF is added to the Lewis basic E atom in2b,2d, and2gwith loss of THF to give P‐tBu (4d), Sb‐tBu (4g)]. By this reaction the antimony‐containing ring2gis kinetically stabilized. Because of the low basicity of the N atom in2ano addition was observed. The ring skeleton of4band4g, undergoes no change by Cr(CO)5coordination as sh

ISSN:0009-2940    

DOI:10.1002/cber.19911241005

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Transition Metal Stannyl Complexes, 4. — Palladium and Platinum Complexes with Chelatting Phosphinoalkylstannyl Ligands by Oxidative Addition of Sn—C BondsReaction of (Ph3P)4Pd with two equivalents of Ph2PCH2CH2‐SnR3(R = Ph, Me) gives the Pd(II) stannyl complexestrans‐Pd(PPh2CH2CH2SnR2)2(2) by oxidative addition of two Sn—R groups and elimination of R—R. Products corresponding to earlier steps of the reaction are obtained by the reaction of (Ph3P)2Pt(C2H4) with Ph2P(CH2)nSnR3(n= 2, 3). The phenylderivatives Ph2P[CH2]nSnPh3afford the Pt(II) complexes (Ph3P)(Ph)PtPPh2[CH2]nSnPh2(3), in which the two phosphorus atoms arecis‐configurated, while Ph2PCH2CH2SnMe3gives the Pt(IV) complexcis,cis,cis‐(Me)2Pt(PPh2CH2CH2SnMe2)2(3) as

ISSN:0009-2940    

DOI:10.1002/cber.19911241006

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractCondensation reactions of cyclopentadienyl‐substituted chlorosilanes CpSiMe2Cl (Cp = C5H5, C5HMe4) with a number of phenols [C6H5OH, 1,3‐C6H4(OH)2, 1,4‐C6H4(OH)2, 1,3,5‐C6H3(OH)3] in the presence of excess base led to six novel molecules containing up to three cyclopentadienyl groups {e.g. 1,3,5‐C6H3[OSiMe2(C5Me4H)]3). The dynamic behavior of 1,4‐C6H4[OSiMe2(C5H5)]2(2) was investigated by temperature‐variable1H NMR and the reaction rate of the degenerate 1,2‐silicon shift determined. C6H5OSiMe2(C5H5) (1) and (2) were treated with NaH, (MeCN)3M(CO)3(M = Mo, W), and Mel to give the η5‐complexes C6H6OSiMe2—(C5H4)M(CO)3Me (8: M = Mo,9: M = W) and 1,4‐C6H4[OSiMe2‐(C5H4)M(CO)3Me]2(10: M = Mo,11: M = W) in good yields. The X‐ray crystal st

ISSN:0009-2940    

DOI:10.1002/cber.19911241007

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Proton Exchange in Re(CO)4(μ‐H)(μ‐PPh2)Mo(η5‐C5H5)(CO)2Against Cationic IB Metal Phosphane SpeciesDecacarbonyldirheniumreacts with hexacarbonylbis(η‐cyclopentadienyl)dimolybdenum and diphenylphosphane to give Re(CO)4(μ‐H)(μ‐PPh2)Mo(η5‐C5H5)(CO)2(1) with a Mo — Re bond as ascertained by an X‐ray structure analysis. The bridging H atom of the heteronuclear metal‐metal bond in1is deprotaned with DBU. The redox condensation reaction of the obtained anion1and triphenylphosphane IB metal cations gave Re(CO)4(μ‐H)(μ‐PPh2)Mo(η5‐C5H5)(CO)2[M = Au (2), Ag (3), and Cu (4)] containing an MReMo triangle. Their yields increase in the sequence of compounds4<3<2. 1,1‐, and2were characterized by cyclovoltammetric meas

ISSN:0009-2940    

DOI:10.1002/cber.19911241008

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

1,3,2‐Diazaborinium Compounds — New Cationic Boron HeteroarenesThe diazaborinium cation9is obtained by the reaction of the vinamidine boron chelate8with Et2O—BF3. The cyclic aluminium compound13forms with the dichloroboranes RBCl2(R = Cl, Et, Ph) the cations15,16a, and16b. AM1 calculations demonstrate the π interaction of the boron with the nitrogen atoms as well as with the fluoro subst

ISSN:0009-2940    

DOI:10.1002/cber.19911241009

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Mono‐, Di‐, and Tricomplexation of 9,10‐Dihydro‐9,10‐dimethyl‐9,10‐diboraanthracene with Fe(CO)3Complex FragmentsReaction of 9,10‐dihydro‐9,10‐dimethyl‐9,10‐diboraanthracene (1c) with (CO)3Fe(C8H14)2gives green (CO)3Fe(η6‐1c) (2c), red [(CO)3Fe]2(η4,η6‐1c) (3c), and orange [(CO)3Fe]3(η4,η4,η6‐1c)(4c). The constitutions of2c, 3c, 4care derived from NMR and MS data and confirmed by X‐ray structure analyses. In2cthe Fe(CO)3group is η6‐bonded to the heterocycle of planar1c. 3cis formed from2cby complexation of the diene of the benzo ring inantiposition. In4cboth benzo rings of2care η4‐bonded to the Fe(

ISSN:0009-2940    

DOI:10.1002/cber.19911241010

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Eight‐Membered BN Rings (RBNR')4from Four‐Membered BN Rings (RBNtBu)2by an Exchange NtBu/NR'Reactions of the four‐membered BN ring compounds (RBNtBu)2(1a–e: R = Me, Et, iPr, iBu, Pr) with azides R'N3(R' = PhCH2, Pr, iBu, Ph) and with the nitrone PhHC=N(Me)=O are studied. The five‐membered ring [=(Me)B=N(tBu)‐N=N‐(PhCH2)N=] (2a) is formed from the four‐membered ring1aand PhCH2N3in the ratio 1:2. An exchange of NtBu for NR' with elimination of tBuN3is observed, however, in the reaction of the ring compounds1b–dwith R'N3. Instead of four‐membered BN rings, the six‐membered BN ring (RBNR')3(3a: R/R' = Et/PhCH2) and the eight‐membered BN rings (RBNR')4(4a–h: R/R' = iPr/PhCH2, iBu/PhCH2, iPr/Pr, iBu/Pr, iPr/iBu, iBu/iBu, Et/Ph, iBu/Ph) are formed, respectively. The NMR spectra reveal diastereotopic methylene protons (Et, Pr, iBu, PhCH2) and methyl groups (iPr, iBu) and thus elucidate the tub‐like structure of the eight‐membered rings.3aand4acrystallize in the space group P2,/c. The reaction of the four‐membered rings1c–ewith the nitrone gives five‐membered rings [=(R)B=N(tBu)=B(R)=N(Me) – O=] (5c–e). Both of the reactions of the four‐membered rings with azides and with the nitrone can be rationalized in term

ISSN:0009-2940    

DOI:10.1002/cber.19911241011

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY