Transition-metal complexes featuring Z-type ligands: Agreement or discrepancy between geometry and dn configuration?

DOI: 10.1002/anie.200703518

Source and publish data:

Angewandte Chemie - International Edition p. 8583 - 8586 (2007)

Update date:2022-08-02

Topics:

Authors:

Sircoglou, Marie

Bontemps, Sebastien

Mercy, Maxime

Saffon, Nathalie

Takahashi, Masashi

Bouhadir, Ghenwa

Maron, Laurent

Bourissou, Didier

Read Full Text PDF DownLoad Join now for total 90,000,000 free articles

Article abstract of DOI:10.1002/anie.200703518

(Chemical Equation Presented) The value of gold: The coordination of ambiphilic diphosphanylborane ligands to AuCl provides unusual square-planar gold(I) complexes. Insight is gained on the nature of the gold→borane interactions in these complexes through

Full text of DOI:10.1002/anie.200703518

Angewandte

Chemie

DOI: 10.1002/anie.200703518

Gold Complexes

Transition-Metal Complexes Featuring Z-Type Ligands: Agreement or

Discrepancy between Geometry and dⁿConfiguration?**

Marie Sircoglou, SØbastien Bontemps, Maxime Mercy, Nathalie Saffon, Masashi Takahashi,

Ghenwa Bouhadir, Laurent Maron,*and Didier Bourissou*

The seminal formalism ML_lX_x(M = transition metal, L = 2e-

donor ligand, X = 1e-donor ligand) provides

a unified

description for transition-metal complexes. Besides the well-

known L- and X-type ligands, the ability of Lewis acids to act

as zero-electron donors/two-electron acceptors was recog-

nized early on,^[1]and these ligands were referred to as Z-type

ligands in ML_lX_xZ_zcomplexes. Although such s-acceptor

ligands remain considerably less developed than their s-

donor counterparts, significant advances have been achieved

over the last decade with Group 13 Lewis acids of the type

ER₃(E = B, Al).^[2–4]In particular, an increasing number and

variety of transition-metal–borane complexes (M!BR₃)

have been unambiguously authenticated.^[5]Following the

pioneering contribution of Hill et al.,^[6]metallaboratranes A

have become general scaffolds for supporting M!BR₃

interactions (M = Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt;

Scheme 1).^[7]The related iridium complex B further expanded

the variety of such interactions to complexes featuring only

two methimazolyl buttresses.^[8]In addition, we have demon-

strated that M!B interactions^[9]are readily accessible by

coordination of preformed ambiphilic phosphanylborane

ligands.^[17–19]The ensuing square-pyramidal complexes C

exemplified the possibility for M!B interactions to exist in

the absence of s-donor ligands in the position trans to the

Lewis acid^[17a]and substantiated the marked influence that the

metal (M = Rh, Pt, Pd) may have on such interactions.^[17d]

Scheme 1. Structurally characterized complexesfeaturing M !BR₃

interactions.

Furthermore, the T-shaped complexes D provided the first

evidence for M!B interactions in 14-electron complexes

supported by a single phosphane buttress.^[17b]

The increasing number and variety of complexes featuring

dative M!B bonds have raised fundamental questions as to

the very nature of such interactions. Accordingly, Hill^[20a]and

Parkin^[20b]proposed two conflicting bonding situations to

describe complexes featuring such Z-type ligands: 1) reten-

tion of the original dⁿconfiguration of the metal center and a

coordinated neutral BR₃ligand, and 2) two-electron oxida-

tion of the metal center resulting in a d^nꢀ2configuration and a

dianionic BR₃^2ꢀligand (Scheme 2). At first glance, these two

[*] M. Sircoglou, Dr. S. Bontemps, Dr. G. Bouhadir, Dr. D. Bourissou

Laboratoire HØtØrochimie Fondamentale et AppliquØe du CNRS

(UMR 5069), UniversitØ Paul Sabatier

118, route de Narbonne, 31062 Toulouse Cedex 09 (France)

Fax: (+33)5-6155-8204

E-mail: dbouriss@chimie.ups-tlse.fr

Scheme 2. The two limiting bonding situations for dative M!BR₃

M. Mercy, Dr. L. Maron

Laboratoire de Physique et Chimie des Nanoobjets (UMR 5215)

INSA, UniversitØ Paul Sabatier

[20a]

interactionsproposed by Hill

and Parkin,^[20b]respectively.

135, avenue de Rangueil, 31077 Toulouse Cedex (France)

Fax: (+33)5-6155-9697

E-mail: laurent.maron@irsamc.ups-tlse.fr

descriptions may be considered as just different representa-

tions of dative M!B bonds, but they in fact reflect two

extreme bonding situations that are intimately related to the

extent of electron-density transfer from the metal atom to the

boron center. In this context, we report herein a combined

experimental and theoretical investigation of [AuCl(diphos-

phanylborane)] complexes featuring short Au–B contacts.

The observed square-planar coordination geometries of the

tetracoordinate gold centers could be considered as indicating

d⁸gold(III) configurations, but natural bond orbital (NBO)

analyses and Mössbauer spectroscopic measurements unam-

biguously established that these complexes retain d¹⁰gold(I)

configurations. These results provide the first evidence that

Dr. N. Saffon

Structure FØdØrative Toulousaine en Chimie MolØculaire (FR 2599),

UniversitØ Paul Sabatier

118, route de Narbonne, 31062 Toulouse Cedex 09 (France)

Dr. M. Takahashi

Department of Chemistry, Faculty of Science, Toho University

Miyama, Funabashi, Chiba 274-8510 (Japan)

[**] The CNRS, the UPS, and the ANR are acknowledged for financial

support of this work. We also thank Dr. P. W. Dyer, Dr. K. Miqueu,

and Dr. J. M. Sotiropoulos for helpful discussions.

Supporting information for thisarticle isavailable on the WWW

under http://www.angewandte.org or from the author.

Angew. Chem. Int. Ed. 2007, 46, 8583 –8586

ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

8583

&&&&

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Take advantage of blue reference links

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Communications

basic principles usually dictating the geometry of transition-

ane ligand featuring a coligand in a position trans to the boron

atom.

metal complexes may be challenged with Z-type ligands.

The diphosphanylborane 1a^[17a,c]readily displaced the

labile dimethyl sulfide ligand of [AuCl(SMe₂)] in dichloro-

methane (DCM) at room temperature (RT; Scheme 3). The

With regards to the bonding description of the M!B

interactions, the square-planar geometry observed in 2a may

indicate a d⁸gold(III) configuration.^[23]Indeed, complexes of

tetracoordinate d¹⁰gold(I) adopt tetrahedral and not square-

planar arrangements.^[24]

To probe substituent effects on M!B interactions, the

isopropyl groups at the phosphorus atoms were replaced by

phenyl moieties. The ligand 1b and ensuing complex 2b were

prepared in a similar manner to 1a and 2a. X-ray diffraction

analysis of 2b revealed an overall geometry very similar to

that of 2a.^[21]Notably, the lower steric hindrance and electron-

donating character of the PPh₂groups does not affect the Au–

P and Au–Cl distances, but results in a slightly elongated Au–

B distance (2.335 ) and a slightly less pronounced pyramid-

alization of the boron environment (ꢀB_a= 343.88).

To address the bonding description of the Au!B

interactions in more detail, DFT calculations were carried

out on the actual complexes 2a,b*.^[25]As previously observed

for related complexes of Group 9 and 10 transition metals, the

B3PW91/SDD(Au,P),6-31G**(other atoms) level of theory

was found to reproduce the experimental geometric features

particularly well (Table 1). The corresponding frontier molec-

Scheme 3. Coordination of the ambiphilic diphosphanylborane ligands

1a,b to AuCl.

resulting complex 2a was isolated in 90% yield as a white, air-

stable powder. The ³¹P NMR spectrum of complex 2a

exhibited a single signal at d = 73.2 ppm, indicating symmetric

coordination of the phosphorus atoms. In addition, the broad

resonance observed at d = 24.6 ppm in the ¹¹B NMR spectrum

of 2a is very similar to that encountered for related rhodium

complexes (d = 19.4–26.7 ppm), suggesting the presence of an

Au!B interaction. The precise structure of 2a was estab-

lished by an X-ray diffraction study (Figure 1).^[21]The gold

Table 1: Experimental and theoretical data for complexes 2a,b and

2a*,b*, respectively. Selected bond lengths [] and angles [8].

P–Au

Au–B

Au–Cl

ꢀ_aB ꢀ_aAu P-Au-P

B-Au-Cl

2a 2.313(2) 2.309(8) 2.522(2) 341.2 362.2 160.2(1) 168.7(2)

2.328(2)

2a*

2.35

2.37

2.32

2.56

340.1 362.5

158.0

170.8

2b 2.307(1) 2.335(5) 2.524(1) 343.8 364.2 157.2 (1) 162.0(2)

2.329(1)

2b*

2.34

2.36

2.35

2.56

343.5 362.9

158.2

168.8

ular orbitals reveal three-center B-Au-Cl interactions. These

interactions involve the d_x₂_ꢀy₂orbital of gold and the p_y

orbitals of boron and chlorine, with bonding gold–boron

and antibonding gold–chlorine interactions in the highest

occupied molecular orbital (HOMO), and antibonding gold–

boron and gold–chlorine interactions in the lowest unoccu-

pied molecular orbital (LUMO; Figure 2). Parkin et al.

Figure 1. Molecular structure (thermal ellipsoids set at 50% probabil-

ity) of complex 2a in the solid state. Hydrogen atoms are omitted for

clarity.

center is tetracoordinate and had a slightly distorted square-

planar coordination geometry (sum of angles (ꢀAu_a) =

362.28). The two phosphane moieties span trans sites with a

significantly bent P-Au-P arrangement (160.28). The B-Au-Cl

arrangement is closer to linear (168.78). The Au–B distance

(2.309 ) is much shorter than those observed in related gold

complexes with monophosphanylborane ligands (2.66–

2.90 ),^[17b]but falls within the same range as those encoun-

tered in rhodium complexes with diphosphanylborane ligands

(2.29–2.37 ).^[17a,d]The presence of a rather strong Au!B

interaction^[22]is further supported by the noticeable pyramid-

alization of the boron environment (ꢀB_a= 341.28). 2a is the

first example of a complex of an ambiphilic phosphanylbor-

Figure 2. Frontier orbitalsfor complex 2a*. Hydrogen atomsare

omitted for clarity.

8584

www.angewandte.org

ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Angew. Chem. Int. Ed. 2007, 46, 8583 –8586

&&&&

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Take advantage of blue reference links

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Angewandte

Chemie

reported similar three-center four-electron interactions for

iridaboratranes and argued for a formal two-electron oxida-

tion/d^nꢀ2configuration of the metal atom on the basis of its

negligible contribution to the nonbonding B-Ir-Cl orbital.^[7g]

Second-order perturbative NBO analyses of 2a,b* also

provided evidence for Au!B dative interactions, with NBO

delocalization energies of about 55 kcalmol^ꢀ1. Notably, the

coordination of the diphosphanylborane ligand induces only a

moderate depletion of the NBO charge at boron (from + 0.85

in the open form of the ligand 1a^[17d]to + 0.37 in the ensuing

complex 2a), which is accompanied by a slight increase of the

charge at gold (from + 0.30 in the model borane-free T-

shaped complex [AuCl(PMe₃)₂] to + 0.64 in 2a). This result

suggests that complexes 2a,b would be more appropriately

described as gold(I) than as gold(III) complexes, as initially

proposed on the basis of geometric considerations. This

hypothesis was further corroborated by the computed natural

electron configuration^[26]of the metal center ([Xe]6s(0.70)5d-

(9.63)6d(0.01)7p(0.01) for 2a), which deviates only margin-

ally from the d¹⁰configuration expected for a gold(I) center

([Xe]6s(0.88)5d(9.79)6p(0.03) computed for [AuCl(PMe₃)₂]).

To support such an unprecedented combination of a

square-planar geometry with a d¹⁰gold(I) configuration,

further experimental evidence was necessary. ¹⁹⁷Au Mössba-

uer spectroscopy, which has previously been used to deter-

mine the structure and bonding of a variety of inorganic gold

compounds,^[27]was considered a particularly valuable probe.

These measurements were performed on both complexes

2a,b to avoid any ambiguity arising from substituent effects.

The resulting spectra consist of well-resolved quadrupole

doublets, with isomer shifts (ISs) of about 3.35 mms^ꢀ1

(relative to a ¹⁹⁶Pt/Pt source, corresponding to 4.57 mms^ꢀ1

relative to gold metal) and quadrupole splittings (QSs) of

about 7.6 mms^ꢀ1(Figure 3a). Although these values are

hardly comparable with those observed for gold complexes

featuring only s-donor ligands, the well-known IS/QS rela-

tionship^[28]unambiguously positions complexes 2a,b among

gold(I) complexes (Figure 3b). These data, thus, definitely

confirm that the square-planar complexes 2a,b should be

considered as complexes of d¹⁰gold(I) rather than d⁸gold-

(III).

In conclusion, the square-planar gold(I) complexes 2a,b

with ambiphilic diphosphanylborane ligands provide a better

understanding of the precise nature of M!BR₃interactions.

It is demonstrated that the coordination of s-acceptor Z-type

ligands to transition metals is not necessarily accompanied by

formal two-electron oxidation. This type of coordination may

eventual challenge the basic rules usually governing the

geometry of transition-metal complexes. Further investiga-

tions in this area are currently in progress with lighter

Group 11 elements, as well as triphosphanylborane ligands.

Experimental Section

All reactions and manipulations were carried out under an atmos-

phere of dry argon, using standard Schlenk techniques.

2a: A solution of 1a (600 mg, 1.26 mmol) in CH₂Cl₂(5 mL) was

added at room temperature to a suspension of [AuCl(SMe₂)] (371 mg,

1.26 mmol) in CH₂Cl₂(5 mL). After stirring for 15 minutes, filtration

of the reaction mixture over SiO₂or Al₂O₃and evaporation of the

volatile components afforded 2a as an air-stable solid (899 mg, 90%

yield). Colorless crystals were obtained from a saturated pentane

solution at room temperature. M.p. 183–1858C; ³¹P NMR

(202.5 MHz, CDCl₃, 238C): d = 73.2 ppm; ¹¹B NMR (160.5 MHz,

CDCl₃, 238C): d = 24.6 ppm; MS (ESI⁺) m/z (%): 707.5 [M+H]⁺

(< 1), 671.3 [MꢀCl]⁺(100); HRMS (ESI⁺) m/z calcd for

[C₃₀H₄₁AuBP₂]⁺: 671.2442; found: 671.2451.

Received: August 2, 2007

Published online: October 8, 2007

Keywords: B,P ligands · donor–acceptor systems ·

electronic structure · gold · Mössbauer spectroscopy

[1] a) R. B. King, Adv. Chem.

Ser. 1967, 62, 203 – 220;

b) M. L. H. Green, J. Orga-

nomet. Chem. 1995 , 500 ,

127 – 148.

[2] Z-type ligands are not

restricted to Lewis acids of

Group 13 elements, as exem-

plified early on with pyrami-

dal h¹-SO₂complexes: G. J.

Kubas, Acc. Chem. Res. 1994 ,

27 , 183 – 190.

[3] For alane complexes, see:

a) J. M. Burlitch, M. E. Leo-

nowicz, R. B. Petersen, R. E.

Hughes, Inorg. Chem. 1979 ,

18 ,

1097 – 1105;

b) J. T.

Golden, T. H. Peterson, P. L.

Holland, R. G. Bergman,

R. A. Andersen, J. Am.

Chem. Soc. 1998 , 120 , 223 –

224; c) H. Braunschweig, K.

Gruss, K. Radacki, Angew.

Chem. 2007 , 119 , 7929 – 7931;

Figure 3. a) ¹⁹⁷Au Mössbauer spectra for complexes 2a,b at 12 K. T=Relative transmission, v=Doppler

velocity. b) QS/IS correlation for complexes 2a,b (red triangles) and representative phosphane complexes

of gold(I) (green squares) and gold(III) (blue circles). IS values are given relative to gold metal.

Angew. Chem. Int. Ed. 2007, 46, 8583 –8586

ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.angewandte.org

8585

&&&&

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Take advantage of blue reference links

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Communications

Angew. Chem. Int. Ed. 2007 , 46 , 7782 – 7784.

Zakharov, W. S. Kassel, A. L. Rheingold, F. Jäkle, Angew. Chem.

2005 , 117 , 5564 – 5569; Angew. Chem. Int. Ed. 2005 , 44 , 5428 –

5433, and references therein.

[4] For a recent reviewon transition-metal complexes of boron, see:

H. Braunschweig, C. Kollann, D. Rais, Angew. Chem. 2006 , 118 ,

5380 – 5400; Angew. Chem. Int. Ed. 2006 , 45 , 5254 – 5274.

[14] a) P. Braunstein, U. Englert, G. E. Herberich, M. Neuschütz,

Angew. Chem. 1995 , 107 , 1090 – 1092; Angew. Chem. Int. Ed.

Engl. 1995 , 34 , 1010 – 1012; b) P. Braunstein, G. E. Herberich, M.

Neuschütz, M. U. Schmidt, U. Englert, P. Lecante, A. Mosset,

Organometallics 1998 , 17 , 2177 – 2182.

[15] F. Jiang, P. J. Shapiro, F. Fahs, B. Twamley, Angew. Chem. 2003 ,

115 , 2755 – 2757; Angew. Chem. Int. Ed. 2003 , 42 , 2651 – 2653.

[16] J. B. Bonanno, T. P. Henry, P. T. Wolczanski, A. W. Pierpont,

T. R. Cundari, Inorg. Chem. 2007 , 46 , 1222 – 1232.

ꢀ

[5] M!B interactions supported by s donation of one or two B H

bonds have been structurally identified. For selected examples,

see: a) J. F. Hartwig, C. N. Muhoro, X. He, O. Eisenstein, R.

Bosque, F. Maseras, J. Am. Chem. Soc. 1996 , 118 , 10936 – 10937;

b) C. N. Muhoro, J. F. Hartwig, Angew. Chem. 1997 , 109 , 1536 –

1538; Angew. Chem. Int. Ed. Engl. 1997 , 36 , 1510 – 1512; c) G.

Alcaraz, E. Clot, U. Helmstedt, L. Vendier, S. Sabo-Etienne, J.

Am. Chem. Soc. 2007 , 129 , 8704 – 8705.

[6] A. F. Hill, G. R. Owen, A. J. P. White, D. J. Williams, Angew.

Chem. 1999 , 111 , 2920 – 2923; Angew. Chem. Int. Ed. 1999 , 38 ,

2759 – 2761.

[17] a) S. Bontemps, H. Gornitzka, G. Bouhadir, K. Miqueu, D.

Bourissou, Angew. Chem. 2006 , 118 , 1641 – 1644; Angew. Chem.

Int. Ed. 2006 , 45 , 1611 – 1614; b) S. Bontemps, G. Bouhadir, K.

Miqueu, D. Bourissou, J. Am. Chem. Soc. 2006 , 128 , 12056 –

12057; c) S. Bontemps, G. Bouhadir, P. W. Dyer, K. Miqueu, D.

Bourissou, Inorg. Chem. 2007 , 46 , 5149 – 5151; d) S. Bontemps,

M. Sircoglou, G. Bouhadir, H. Puschmann, J. A. K. Howard,

P. W. Dyer, K. Miqueu, D. Bourissou, Chem. Eur. J. 2007, DOI:

10.1002/chem.200701027.

[18] For a related heterobimetallic complex with a PSB ligand, see:

S. R. Oakley, K. D. Parker, D. J. H. Emslie, I. Vargas-Baca, C. M.

Robertson, L. E. Harrington, J. F. Britten, Organometallics 2006 ,

25 , 5835 – 5838.

[19] For reversible H₂capture by a phosphanylborane derivative, see:

a) G. C. Welch, R. R. San Juan, J. D. Masuda, D. W. Stephan,

Science 2006 , 314 , 1124 – 1126; for the derivatization of phos-

phanylborane compounds into photoisomerizable systems, see:

b) M. W. P. Bebbington, S. Bontemps, G. Bouhadir, D. Bour-

issou, Angew. Chem. 2007 , 119 , 3397 – 3400; Angew. Chem. Int.

Ed. 2007 , 46 , 3333 – 3336.

[7] a) M. R. St.-J. Foreman, A. F. Hill, A. J. P. White, D. J. Williams,

Organometallics 2004 , 23 , 913 – 916; b) I. R. Crossley, A. F. Hill,

Organometallics 2004 , 23 , 5656 – 5658; c) D. J. Mihalcik, J. L.

White, J. M. Tanski, L. N. Zakharov, G. P. A. Yap, C. D. Incar-

vito, A. L. Rheingold, D. Rabinovitch, Dalton Trans. 2004 , 1626 –

1634; d) I. R. Crossley, M. R. St.-J. Foreman, A. F. Hill, A. J. P.

White, D. J. Williams, Chem. Commun. 2005 , 221 – 223; e) I. R.

Crossley, A. F. Hill, E. R. Humphrey, A. C. Willis, Organo-

metallics 2005 , 24 , 4083 – 4086; f) I. R. Crossley, A. F. Hill, A. C.

Willis, Organometallics 2006 , 25 , 289 – 299; g) V. K. Landry, J. G.

Melnick, D. Buccella, K. Pang, J. C. Ulichny, G. Parkin, Inorg.

Chem. 2006 , 45 , 2588 – 2597; h) R. J. Blagg, J. P. H. Charmant,

N. G. Connelly, M. F. Haddow, A. G. Orpen, Chem. Commun.

2006 , 2350 – 2352; i) J. S. Figueroa, J. G. Melnick, G. Parkin,

Inorg. Chem. 2006 , 45 , 7056 – 7058; j) K. Pang, S. M. Quan, G.

Parkin, Chem. Commun. 2006 , 5015 – 5017; k) S. Senda, Y. Ohki,

T. Hirayama, D. Toda, J.-L. Chen, T. Matsumoto, H. Kawaguchi,

K. Tatsumi, Inorg. Chem. 2006 , 45 , 9914 – 9925; l) I. R. Crossley,

A. F. Hill, A. C. Willis, Organometallics 2007 , 26 , 3891 – 3895.

[8] I. R. Crossley, A. F. Hill, A. C. Willis, Organometallics 2005 , 24 ,

1062 – 1064.

[9] The contribution of M!B interactions has also been pointed out

in tantalocene–borataalkene complexes,^[10]boryl-bridged com-

plexes,^[11](metallo)borylene complexes,^[12]borylmetallocenes,^[13]

heterometallic borole complexes,^[14]bis(phosphanemethylenido)-

borane complexes,^[15]and borane adducts of [Ta(OSit-Bu₃)₃].^[16]

[10] K. S. Cook, W. E. Piers, R. McDonald, J. Am. Chem. Soc. 2002 ,

124 , 5411 – 5418, and references therein.

[11] a) D. Curtis, M. J. G. Lesley, N. C. Norman, A. G. Orpen, J.

Starbuck, J. Chem. Soc. Dalton Trans. 1999 , 1687 – 1694; b) S. A.

Westcott, T. B. Marder, R. T. Baker, R. L. Harlow, J. C. Calabr-

ese, K. C. Lam, Z. Lin, Polyhedron 2004 , 23 , 2665 – 2677; c) H.

Braunschweig, K. Radacki, D. Rais, G. R. Whittell, Angew.

Chem. 2005 , 117 , 1217 – 1219; Angew. Chem. Int. Ed. 2005 , 44 ,

1192 – 1193.

[20] a) A. F. Hill, Organometallics 2006 , 25 , 4741 – 4743; b) G. Parkin,

Organometallics 2006 , 25 , 4744 – 4747.

[21] CCDC-656214 (2a) and CCDC-656215 (2b) contain the supple-

mentary crystallographic data for this paper. These data can be

obtained free of charge from The Cambridge Crystallographic

Data Centre via www.ccdc.cam.ac.uk/data_request/cif.

[22] For supported and unsupported interactions between gold(I)

and Group 13 elements, see: a) M. Bardajꢀa, A. Laguna, Eur. J.

Inorg. Chem. 2003, 3069 – 3079; b) E. J. Fernꢁndez, A. Laguna,

J. M. Lꢂpez-de-Luzuriaga, M. Monge, M. Nema, M. E. Olmos, J.

Pꢃrez, C. Silvestru, Chem. Commun. 2007, 571 – 573.

[23] Concordant geometry and d⁸configuration in palladaboratranes

were assumed by Parkin et al.^[7j]

[24] M. A. Carvajal, J. J. Novoa, S. Alvarez, J. Am. Chem. Soc. 2004 ,

126 , 1465 – 1477.

[25] For a recent reviewon the theoretical chemistry of gold, see: P.

Pyykkö, Angew. Chem. 2004 , 116 , 4512 – 4557; Angew. Chem.

Int. Ed. 2004 , 43 , 4412 – 4456.

[12] a) H. Braunschweig, D. Rais, K. Uttinger, Angew. Chem. 2005 ,

117 , 3829 – 3832; Angew. Chem. Int. Ed. 2005 , 44 , 3763 – 3766;

b) H. Braunschweig, K. Radacki, D. Rais, F. Seeler, Angew.

Chem. 2006 , 118 , 1087 – 1090; Angew. Chem. Int. Ed. 2006 , 45 ,

1066 – 1069; c) H. Braunschweig, C. Burschka, M. Burzler, S.

Metz, K. Radacki, Angew. Chem. 2006 , 118 , 4458 – 4461; Angew.

Chem. Int. Ed. 2006 , 45 , 4352 – 4355.

[13] a) M. Scheibitz, M. Bolte, J. W. Bats, H.-W. Lerner, I. Nowik,

R. H. Herber, A. Krapp, M. Lein, M. C. Holthausen, M. Wagner,

Chem. Eur. J. 2005 , 11 , 584 – 603; b) K. Venkatasubbaiah, L. N.

[26] For a previous use of natural electron configuration in the study

of metal–ligand interactions, see: L. Maron, O. Eisenstein, J.

Phys. Chem. A 2000 , 104 , 7140 – 7143.

[27] a) R. V. Parish in Mꢀssbauer Spectroscopy Applied to Inorganic

Chemistry (Ed.: G. J. Long), Plenum, NewYork, 1984; b) L. S.

Moore, R. V. Parish, R. Usꢂn, A. Laguna, M. Laguna, M. N.

Fraile, J. Chem. Soc. Dalton Trans. 1988 , 23 – 26; c) S. K.

Bhargava, F. Mohr, M. Takahashi, M. Takeda, Bull. Chem.

Soc. Jpn. 2001 , 74 , 1051 – 1053.

[28] See the Supporting Information for details.

8586

www.angewandte.org

ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Angew. Chem. Int. Ed. 2007, 46, 8583 –8586

&&&&

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Take advantage of blue reference links

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Products guided by the article

Product name:(B(C₆H₄P(CH(CH₃)2)2)2(C₆H₅))AuCl

Cas No:1003001-73-7

R&D Labs maybe for 1003001-73-7

Jiaozuo Zhongwen Trading Coporation Limited

Contact:+86 0391-3553810

Address:East Renmin Road
Pale Palm Imex

Contact:+36(21)2523420

Address:Head office: 1102 Budapest, SZENT LASZLO TER 24/B. 1/1., HUNGARY / CHINA
Shandong Jiulong Hisince Pharmaceutical Co.,Ltd.

Contact:+86-15853188990

Address:Huadian Pioneer Park, Huadian Township, Qihe County, Dezhou City, Shandong, P.R.China
TIANJIN ZHONGXIN CHEMTECH CO.,LTD.

Contact:86-022-89880739

Address:10B, Pan China International Center, No. 931 YingKou Road, TangGu, Tianjin, China, 300451
Anhui Sholon New Material Technology Co., Ltd.

website:http://www.sholonchem.com

Contact:+86-550-5261666

Address:4/F Block B, Beijing Chemical Building.No.520 Tianrun Road ,Science & Education Town Wujin District, Changzhou City Jiangsu Province

Relevant to this article

Dynamic Stereochemistry of Imines and Derivatives. 19. Mutarotation and E - Z Izomerization of Chiral Imines in <2H4> Methanol Solution

Doi:10.1021/jo00357a007
(1986)
Synthesis of flaccidoside II, a bidesmosidic triterpene saponin isolated from Chinese folk medicine Di Wu

Doi:10.1016/j.carres.2007.11.015
(2008)
Synthesis of a versatile metacyclophane macrolactam

Doi:10.1016/j.tetlet.2007.10.150
(2008)
Doi:10.1021/jo01258a019
(1969)
Evaluation of enantiopure N-(ferrocenylmethyl)azetidin-2-yl(diphenyl) methanol for catalytic asymmetric addition of organozinc reagents to aldehydes

Doi:10.1021/jo701943x
(2008)
Harnessing Alkylpyridinium Salts as Electrophiles in Deaminative Alkyl-Alkyl Cross-Couplings

Doi:10.1021/jacs.9b00111
(2019)

Article Doi

Transition-metal complexes featuring Z-type ligands: Agreement or discrepancy between geometry and dn configuration?

DOI: 10.1002/anie.200703518

Source and publish data:

Authors:

Article abstract of DOI:10.1002/anie.200703518

Full text of DOI:10.1002/anie.200703518

Products guided by the article

R&D Labs maybe for 1003001-73-7

Relevant to this article

Hot Product