Coordination of noble metals by an ambiphilic PBiP pincer ligand: Metallophilic Bi–Cu and Bi–Ag interactionsJournal of Organometallic Chemistry


Carolin Tschersich, Beatrice Braun, Christian Herwig, Christian Limberg
Inorganic Chemistry / Organic Chemistry / Physical and Theoretical Chemistry / Materials Chemistry / Biochemistry


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Bismuth d P we -Cl) t/va al p troscopic results, to monomeric complexes, which, however, aggregate in course of the crystallization process to give [M(anion)(PBiP)]x. © 2014 Elsevier B.V. All rights reserved. bism nd it we [1a plexe belonging to trivalent compounds of the lighter pnictogenes.

Although some compounds have been isolated, which show that bismuthanes principally can act as donor ligands for transition metal ions [2], their number is rather limited. Recently, a further oraneously with F. metal / bismuth here the donating ]. Since in particdrocarbon transguing facet: The catalytic activity

Lewis acidic bismuth moieties, whose properties in turn can be tuned via the electronegativity of the connected co-ligands, appears highly attractive.

In case of gold(I) metallophilic dispersive interactions can be enhanced significantly by relativistic effects, and so it appeared interesting to compare with the cases of silver(I) and copper(I), where these are not existent. Here we describe the results obtained employing PBiP for the complexation of CuI and AgI, two further metals which effectively mediate hydrocarbon conversions. * Corresponding author. Tel.: þ49 30 20937382.

Contents lists availab

Journal of Organom sev

Journal of Organometallic Chemistry xxx (2014) 1e7E-mail address: (C. Limberg).considering that bismuth is a group 5 element, a further possibility immediately suggests itself: The coordination of bismuth(III) donor atoms at Lewis acidic metal centers, analogously to phosphane complexes. However, bismuth is the heaviest of the pnictogenes, in fact it is the heaviest of the stable elements, and thus it shows a unique character. For instance the 6s2 lone pair is stabilized by pronounced relativistic effects, and thus its donor strength is much lower than the strengths of the lone pairs third type of metallophilic interaction contemp

Gabbai and co-workers: the first examples of donoreacceptor interactions were reported, w metal ions were PtII, PdII and AuI (Scheme 1) [4 ular late-transition metals also mediate hy formations this finding has a further intri possibility to influence the reactivity and (selectivity) of a late-metal complex entity byof which were shown to represent interesting precursor compounds for hydrocarbon conversion [1d]. On the other hand, lizing an ambiphilic PBiP pincer ligand (see Scheme 1) [4a] that had been specially designed for this purpose we have realized thisPincer



There are two obvious ways for lophilic interactions. On the one ha muthemetal bonds, and in the past been concerned a lot with BieM com 0022-328X/© 2014 Elsevier B.V. All rights reserved.

Please cite this article in press as: C. j.jorganchem.2014.09.019uth to undergo metalcan form covalent bis] and others [1b,c] have s, some representatives option for bismuth to interact with other metals has been revealed, that is based on the fact that BiIII compounds can also show distinct Lewis acidic properties, especially if electronegative ligands, X, are bound, as this leads to anti-bonding s*(BidX) acceptor orbitals (“secondary bonding”) [3]. This opens the opportunity for electron-rich metals to donate to bismuth, and uti-Noble metal

Ambiphilic ligandsCoordination of noble metals by an amb

Metallophilic BieCu and BieAg interact

Carolin Tschersich, Beatrice Braun, Christian Herwi

Institut für Chemie, Humboldt-Universit€at zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin, G a r t i c l e i n f o

Article history:

Received 12 July 2014

Received in revised form 10 September 2014

Accepted 13 September 2014

Available online xxx a b s t r a c t

Reaction of the pincer ligan

M/Bi interactions, which series of compounds [Cu(m distances and the covalen teractions. Employing met journal homepage: www.elTschersich, et al., Journalhilic PBiP pincer ligand: ns

Christian Limberg* any

BiP with MCl (M ¼ Cu, Ag) led to the complexes [M(m-Cl)(PBiP)]2 featuring re shown by DFT/NBO to have predominantly Bi / M character. In the (PBiP)]2, [Ag(m-Cl)(PBiP)]2 and [AuCl(PBiP)] the ratios between the MeBi n der Waals radii decrease, which indicates a strengthening of the inrecursors with weakly interacting anions leads, according to NMR specle at ScienceDirect etallic Chemistry ier .com/locate/ jorganchemof Organometallic Chemistry (2014), anomExperimental

General considerations

All manipulations were carried out in a glovebox or by means of

Schlenk-type techniques involving the use of a dry and oxygen-free argon atmosphere. All solvents were dried by an MBraun SPS solvent purification system prior to use. CuCl, AgCl and [Cu(MeCN)4]

BF4 were purchased from Sigma Aldrich and AgOTf was obtained from ABCR. PBiP was prepared according to literature procedure [4a].

The 1H, 13C{1H}, 31P{1H} and 19F NMR spectrawere recorded on a

Bruker AV or DPX 300 (1H, 300.13 MHz; 13C{1H}, 75.47 MHz; 31P {1H}, 121.5 MHz; 19F{1H}, 282.404 MHz), a Bruker AV 400 (1H, 400.13 MHz) or a Bruker AV 500 NMR (1H, 300.13 MHz) spectrometer in dry deoxygenated CD2Cl2 or [D5]pyridine as solvent.

The spectrawere calibrated against the internal residual proton and natural abundance 13C resonances of the deuterated solvent (CD2Cl2 dH 5.32 ppm, dC 53.84 ppm; [D5]pyridine dH 8.71, 7.55, 7.19 ppm, dC 149.5, 135.5, 123.5 ppm). Chemical Shifts of 31P nuclei are referenced externally to H3PO4 and those of 19F nuclei to CFCl3.

The following abbreviations are used for the peak multiplicities: s, singlet; d, doublet; t, triplet; m, multiplet; bs, broad singlet; bm, broad multiplet. Mass spectra (ESI) were recorded on an Agilent

Technologies 6210 Time-of-Flight LC-MS instrument. Microanalyses were performed on a HEKAtech Euro EA 3000 elemental analyzer. Infrared (IR) spectra were recorded in the region 4000e400 cm1 using solid samples prepared as KBr pellets with a

Shimadzu FTIR-8400s spectrometer.