摘要:

AbstractElectrochemical investigations on a selection of methylenephosphines1and related systems are reported. They are shown to possess an irreversible oxidation and reduction wave. An exception is diaminodiphosphene, which reversibly forms a radical anion. A relative ordering of frontier orbitals is possible, based on the redox properties of these systems.

ISSN:0009-2940    

DOI:10.1002/cber.19911240302

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Scavenging of Hexafluoroselenoacetone by Cycloadditions with Dienes and Preparation of Hg[SeCF(CF3)2]2and (CH3)3SiSeCF(CF3)2Bis(perfluoroisopropylseleno)mercury (2) was obtained from 2,2,4,4‐tetrakis(trifluoromethyl)‐1,3‐diselenetane (1) and HgF2in DMF, and (perfluoroisopropylseleno)trimethylsilane (3) from2and (CH3)3Sil. The reaction of2with (C2H5)2All as well as the pyrolysis of1yield a deep purple liquid in very small amounts, not sufficient for further characterisation, which is assumed to be hexafluoroselenoacetone (4). However,4is formed as an intermediate in the reaction of hexafluoropropene with CsF and selenium and can be trapped by isoprene or anthracene to form5a, 5b, and6, respectively. In boiling benzene a transformation of (CF3)2CSe from6to 2,3‐dimethyl‐1,3‐butadiene is accomplished yielding7in a retro Diels

ISSN:0009-2940    

DOI:10.1002/cber.19911240303

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

[(BH6)2]S4]2−, [(BH2)Se4]2−: New Chalcogenoboron Hydride Anions with Adamantane StructureThe reaction of THF·BH3/NaBH4(2: 1) with H2S produces Na[H3B‐μ2‐S(B2H5)] (5) with hydrogen evolution.5reacts with an excess of H2S to give Na2[(BH2)6S4] (3a), which is also formed in the reaction of THF·BH3with NaSH or anhydrous Na2S. These reactions proceed via5and the intermediates7or8by loss of BH–4and cyclization. The analogous compound Na2[(BH2)6Se4] (4a) is obtained by the reaction of elemental selenium with NaBH4(1:1) in triglyme. The primary product is Na2[H3B–Se–Se–BH3] (9). Treatment of9at 100 – 110°C yields4aand polymers,3aand4areact with CsBr to form the crystalline compounds Cs2[(BH2)6Se4]·CsBr (3b) and Cs2–[(BH2)6Se4]·CsBr (4b), characterized by X‐ray structure determinations. The anions of3band4bconsist of an adamantane skeleton. The Br−ion is octahedrally coordinated by Cs+ions. The Cs6Br octahedra share faces to form columns along the hexagonal c axis. The crystal structures of the isotypic compounds3band4bare closely relate

ISSN:0009-2940    

DOI:10.1002/cber.19911240304

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Sulfur(IV) Compounds as Ligands, XIII. – Sulfur Dioxide as a Bridging Ligand in Unsymmetrical Dinuclear ComplexesA series of known or newly synthesized dinuclear complexes with the following combinations of elements: Mo/Ir, Mo/Pd, W/Pd, Mn/Pd, Fe/Rh, Rh/Pt, Ir/Pd, and Ir/Pt has been treated with sulfur dioxide. Only electron‐rich systems are capable of taking up SO2into a bridging position. [Mo(CO)3(η2‐dppe) (η1‐dppm)] (2) reacts with [PdCl2(C8H12)] to form [MoPdCl2(CO)3(dppe)(μ‐dppm)] (3), which is unstable and does not take up SO2. However, the complexes [FeRhCl(CO)4(μ‐SO2)(μ‐dppee)] (5), [MoIr(μ‐Cl)(CO)3(μ‐SO2)(μ‐dppm)2] (8), and [MnPdBr(CO)2(μ‐SO2)(μ‐dppm)2] (14) have been obtained. Reactions offac;‐[M(CO)3(η2‐dppm)(η1‐dppm)] (MMo:6a, W: 6b) or the correspondingmer‐isomers10a, bwith [PdCl2;‐(C8H12)] give the dinuclear complexes [MPdCl(μ‐Cl)(CO)2(μ‐CO)(μ‐dppm)2] (11a, b). From [Ir(CO)(dppm)2]Cl and [Pd(dba)2] in the presence of CO [IrPdCl(CO)2(μ‐dppm)2] (16) is obtained, whereas in dichloromethane under an inert gas the oxidation product [IrPdC]3(CO)(μ‐dppm)2] (17) is formed.11a, b, 16, and17apparently are too electron‐poor to form stable adducts with SO2. However, from17and (Me3Si)2S the sulfur‐bridged complex [IrPdCl(μ‐S)(CO)(μ‐dppm)2] (18) is obtained. The alkynyl complexes [MPtCl(CCPh)2(μ‐dppm)2] (M  Rh:19, Ir:21) readily add SO2, reversibly in the case of19. From [IrPtCl‐(C  CPh)2(μ‐SO2)](μ‐dppm)2] (22) the salt [IrPt(C  CPh)2(SO2) (μ‐dppm)2]PF6(23) is formed by Cl a

ISSN:0009-2940    

DOI:10.1002/cber.19911240305

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Various Coordinations in (η2‐Alkene)(η5‐cyclopentadienyl)organylnickel(II) ComplexesA series of (η2‐alkene)(η5‐cyclopentadienyl)organylnickel(II) complexes with substituted cyclopentadienyl ligands is synthesized in order to compare the structures, the thermal stabilities, and chemical reactivities. In (allyl)(η5‐Cp')Ni compounds the allyl moiety is η3‐coordinated when Cp'=C5H5, C5Me5(1), C5Ph5(2), indenyl (3), [Hydridotri(pyrazolyl)borato] (4) (as an equivalent of the cyclopentadienyl ligand), and [C5H4((CH2)3CHCH2)] (22). It is found that the [(η2‐alkene)alkyl(η5‐Cp')nickel] compounds [Cp'=C5Me5; alkeneC2H4, alkyl=Me (10), Et (9) or alkene=(1 – 2‐η2)‐1,3‐butadiene, alkyl=Me (11); Cp'=C5Ph5; alkene=C2H4, alkyl=Me (12)] are thermally more stable and less reactive than their η5;‐ C5H5analogues; the largest increase in thermal stability is observed when the η5‐Cp' and the η2‐alkene functions are connected by substitution of the cyclopentadienyl ligand with an alkenyl group of suitable chain length. In the case of compounds of the general type [(η5‐C5R4((CH2)nCHCH2))‐(ligand)Ni(II)] with Ph3P as the ligand these complexes are cationic [RH,n=3 (14+) or RMe,n=2 (17+)]. On the other hand, the compounds with anionic ligands are neutral complexes (RH,n=3, ligand=methyl (19), ethyl (20), isopropyl (21) or RMe,n=3 and ligand=iodide (24), bromide (25), methyl (26), ethyl (27)]. In14+,17+,19–21and24–27the CC bond of the alkenyl group is η2‐coordinate

ISSN:0009-2940    

DOI:10.1002/cber.19911240306

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Synthesis of Trinuclear Carbonylmanganates and Their Reaction Products with InCl3; X‐ray Structure Determinations of K3[Mn3(μ‐CO)2(CO)10], [(C6H5)4As]2[(μ‐H)Mn3(μ‐CO)10], [{(C6H5)3P}2N]2[μ‐H)Mn3(CO)12], [(C6H5)4As]2[{μ‐H)Mn3(CO)12}2(μ4‐In)] und [(C6H5)4As]2[{(μ‐H)Mn3(CO)12}(μ3‐In){Mn(CO)5}Cl]Mn2(CO)10reacts with KOH in aqueous solution to give the potassium carbonylmanganate K3[Mn3(μ‐CO)2(CO)10] (1). The trianion1is isoelectronic with Fe3(CO)12and is protonated with methanol to form the μ‐hydrido cluster [(μ‐H)Mn3;‐(CO)12]3⊖, which is precipitated with [{(C6H5)3P}2N]Cl as [{(C6H5)3P}2N]2[(μ‐H)Mn3(CO)12] (2), whereas the carbonyl‐bridged μ‐hydrido species [(μ‐H)Mn3(μ‐CO)2(CO)10]2⊖seems to be trapped as the [(C6H5)4As]⊕salt3. The reaction of3with InCl3yields the Mn‐In clusters [(C6H5)4As]2[{(μ‐H)Mn3(CO)12}2;‐(μ4‐In) (4) and [(C6H5)4As]2[{(μ‐H)Mn3(CO)12}(μ3‐In){Mn(CO)5}Cl]

ISSN:0009-2940    

DOI:10.1002/cber.19911240307

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

The tricarbonyl(cyclobutabenzene)chromium(O) complexes12–20, have been prepared from the free ligand and triammintricarbonylchromium(O) or hexacarbonylchromium(O). The complexes have been characterized by spectroscopic methods (IR,1H NMR,13C NMR) and mass spectrometry, and1H‐NMR signal assignments have been verified by an NOE experiment. Diastereomeric ratios have been determined by1H NMR and the diastereomers of the 1‐methyl derivative16separated by HPLC. A crystal‐structure analysis is presented forexo;‐16. A photochemical ligand exchange takes place in 70% yield for the 1‐trimethylsilyl derivative19. Metalation withn‐butyl‐lithium/tmeda at –78°C has been observed only for the aromatic and not for th

ISSN:0009-2940    

DOI:10.1002/cber.19911240308

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

ISSN:0009-2940    

DOI:10.1002/cber.19911240309

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Metal Chelates of Medical Interest, I. –99mTc Complexes with Hexadentate Tricatechol LigandsThe tricatechol ligand tris[3‐(2,3‐dihydroxyphenoxy)propyl]‐amine hydrochloride, TRIPACE (9), is prepared from tris(3‐chlorpropyl)amine (5) and the potassium salt of 2,2‐dimethyl‐1,3‐benzodioxol‐4‐ol (7). This ligand is capable of reducing the99m[TcO4]−ion to lower valent99mTc and subsequent complexation of the reduced99mTc ion. The structures of5and of tris[3‐(2,2‐dimethyl‐1,3‐benzodioxol‐4‐yloxy)propyl]amine (8) ar

ISSN:0009-2940    

DOI:10.1002/cber.19911240310

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

Metal Chelates of Medical Interest, III. –99mTc Complexes with Tetradentate Dicatechol LigandsThe dicatechol ligand bis[3‐(2,3‐dihydroxyphenoxy)propyl]‐amine hydrochloride, DIPACE (6), reduces the99m[TcO4]−ion to lower valent99mTc and subsequently forms a complex with the reduced99mTc. The structure of benzylbis[3‐(2,2‐dimethyl‐1,3‐benzodioxol‐4‐yloxy)propyl]amine (4) is determined by

ISSN:0009-2940    

DOI:10.1002/cber.19911240311

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY