Experimental and Computational Studies on the Formation of Thorium–Copper Heterobimetallics

Article abstract of DOI:10.1002/chem.201603519

The formation of actinide–transition metal heterobimetallics mediated by a terminal actinide imido complex was comprehensively studied. The reaction of the thorium imido complex [(η⁵-C₅Me₅)₂Th=N(mesityl)(DMAP)] (3), prepared from [(η⁵-C₅Me₅)₂ThMe₂] (1) and mesitylNH₂or [(η⁵-C₅Me₅)₂Th(NHmesityl)₂] (2) in the presence of 4-(dimethylamino)pyridine (DMAP), with copper(I) halides gave the first thorium–copper heterobimetallic compounds [(η⁵-C₅Me₅)₂Th(X){N(mesityl)Cu(DMAP)}] (X=Cl (4), Br (5), I (6)). Complexes 4–6 feature an unusual geometry with a short Th?Cu distance, which DFT studies attribute to a weak donor–acceptor bond from the Cu⁺atom to the electropositive Th⁴⁺atom. They are reactive species, as was shown by their reaction with the dimethyl complex [(η⁵-C₅Me₅)₂ThMe₂] (1). Furthermore, a comparison between Th and early transition metals confirmed that Th⁴⁺exhibits distinctively different reactivity from d-transition metals.

Full text of DOI:10.1002/chem.201603519

DOI: 10.1002/chem.201603519
Communication
&
Donor–Acceptor Systems
Experimental and Computational Studies on the Formation of
Thorium–Copper Heterobimetallics
Pikun Yang+,[a] Enwei Zhou+,[a] Guohua Hou,[a] Guofu Zi,*[a] Wanjian Ding,*[a] and
Marc D. Walter*[b]
and selenium (Se), silanes, borane, internal acetylenes, nitriles,
Abstract: The formation of actinide–transition metal het-
ketones, CS2, isothiocyanates, carbodiimides, to organic azides
erobimetallics mediated by a terminal actinide imido com-
and diazoalkane derivatives.[8] Encouraged by this broad spec-
plex was comprehensively studied. The reaction of the
trum of different substrates, we have set out to probe the re-
thorium imido complex [(h5-C5Me5)2Th=N(mesityl)(DMAP)]
activity of actinide imido species in the construction of acti-
(3), prepared from [(h5-C5Me5)2ThMe2] (1) and mesitylNH2
nide–transition metal bonds. Herein, we detail the preparation
of the thorium imido species [(h5-C5Me5)2Th=N(mesityl)-
or [(h5-C5Me5)2Th(NHmesityl)2] (2) in the presence of 4-(di-
methylamino)pyridine (DMAP), with copper(I) halides gave
the first thorium–copper heterobimetallic compounds [(h5-
(DMAP)] (3) and its reactivity toward copper(I) halides to form
heterobimetallic thorium–copper compounds.
C5Me5)2Th(X){N(mesityl)Cu(DMAP)}] (X=Cl (4), Br (5), I (6)).
Reaction of [(h5-C5Me5)2ThMe2] (1) with two equivalents of
Complexes 4–6 feature an unusual geometry with a short
mesitylNH2 in toluene gave the bis(anilido) metallocene [(h5-
ThꢀCu distance, which DFT studies attribute to a weak
C5Me5)2Th(NHmesityl)2] (2) in good yield (Scheme 1). Its molec-
donor–acceptor bond from the Cu+ atom to the electro-
positive Th4+ atom. They are reactive species, as was
shown by their reaction with the dimethyl complex [(h5-
C5Me5)2ThMe2] (1). Furthermore, a comparison between Th
and early transition metals confirmed that Th4+ exhibits
distinctively different reactivity from d-transition metals.
Uranium imido compounds are well studied,[1–3] whereas the
related thorium species are still an area in its infancy, and only
a few examples of structurally well-characterized representa-
tives are known.[3j,4] The electronic ground state of Th is [Rn]
6d27s2, which resembles those observed for early transition
metals, such as Sc, Ti, Zr, and Hf for which several complexes
with M=N bonds are known.[5,6] Because of their similar elec-
tronic ground state comparable reactivity to those of early
transition metals might be envisioned, which also addresses
the question whether 5f orbitals actively participate in the
bonding of organothorium compounds.[7] To answer this ques-
tion, a base-free terminal thorium imido complex [h5-1,2,4-
(Me3C)3C5H2]2Th=N(p-tolyl) was prepared that readily reacted
with various small molecules ranging from elemental sulfur (S8)
[a] P. Yang,+ E. Zhou,+ Dr. G. Hou, Prof. G. Zi, Dr. W. Ding
Department of Chemistry, Beijing Normal University
Beijing 100875 (P.R. China)
E-mail: gzi@bnu.edu.cn
dingwanjian@bnu.edu.cn
[b] Dr. M. D. Walter
Institut fꢀr Anorganische und Analytische Chemie
Technische Universitꢁt Braunschweig
Hagenring 30, 38106 Braunschweig (Germany)
E-mail: mwalter@tu-bs.de
[+] These authors contributed equally to this work.
Supporting information for this article can be found under http://
dx.doi.org/10.1002/chem.201603519.
Scheme 1. Synthesis of complexes 2–9.
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Figure 2. Molecular structure of 3 (thermal ellipsoids are drawn at the 35%
probability level).
The solid-state crystal structure of 3 is presented in Figure 2.
The short ThꢀN(1) distance of 2.091(7) ꢁ and the approximate-
ly linear Th-N-C angle (167.2(6)8) are consistent with a Th=N
double bond.[9] These values agree favorably with those found
in the related [(h5-C5Me5)2Th=N(2,6-Me2C6H3)(THF)] (d(ThꢀN)=
2.045(8) ꢁ, a(Th-N-C)=171.5(7)8)[4a] and with those observed
for [h5-1,2,4-(Me3C)3C5H2]2Th=N(p-tolyl) (d(ThꢀN)=2.038(3) ꢁ,
a(Th-N-C)=172.8(3)8).[8b] The relatively long ThꢀN(2) distance
of 2.554(7) ꢁ is consistent with a datively coordinated nitrogen
atom, and it can be compared to that observed in [(h5-1,2,4-
(Me3C)3C5H2)2Th(O)(DMAP)] (2.587(5) ꢁ).[8a] A DFT study reveals
that the thorium–nitrogen double bond (Th=N) in 3 is strongly
polarized and more adequately described as Th+ꢀNꢀ (see the
Supporting Information for details).
Figure 1. Molecular structure of 2 (thermal ellipsoids are drawn at the 35%
probability level).
ular structure is shown in Figure 1. The Th4+ ion is h5-bound to
two C5Me5 ligands and s-coordinates to the nitrogen atoms of
the two anilido groups mesitylNH in a distorted-tetrahedral ge-
ometry with an average ThꢀC(ring) distance of 2.825(13) ꢁ and
the Cp(cent)-Th-Cp(cent) angle of 130.9(6)8 and the N(1)-Th-
N(2) angle of 115.3(6)8. The average ThꢀN distance of
2.344(12) ꢁ is significantly longer than that found in [(h5-1,2,4-
(Me3C)3C5H2)2Th(HNMe)2] (2.241(4) ꢁ), but comparable to that
Based on the electronic structure of the moiety Th=N(mesi-
tyl) (for details, see the Supporting Information), significant re-
activity toward electrophiles or Lewis acids can be expected.
But although the reaction of the related uranium(IV) imido
complexes with copper(I) halides induces an one-electron oxi-
dation to UV,[3o,p] addition of one equivalent of copper(I) halides
(CuX) to the thorium imido moiety of 3 gave the thorium–
observed
in
[(h5-1,2,4-(Me3C)3C5H2)2Th(HN-p-tolyl)2]
(2.283(3) ꢁ),[8b] which presumably reflects the increased steric
hindrance of the mesitylNHꢀ group. Therefore, complex 2
should also be more reactive than the less sterically encum-
copper
heterobimetallic
compounds
[(h5-
bered
bis(amido)
compound
[(h5-1,2,4-
C5Me5)2Th(X){N(mesityl)Cu(DMAP)}] (X=Cl (4), Br (5), I (6)) in
quantitative conversions (Scheme 1). DFT investigations sug-
gest that the DMAP initially dissociates from 3 to give the
imido intermediate INTa (Figure 3). In a next step, the Th=N
functionality coordinates to the Cu atom of CuI, forming the
intermediate INTb. Finally, an intermolecular nucleophilic
attack between INTb and DMAP occurs to give the product 6
(Me3C)3C5H2)2Th(HNMe)2],[8b] which was confirmed by the ther-
mal decomposition of 2 at approximately 1508C (see the Sup-
porting Information for details). Furthermore, in contrast to the
reaction of [(h5-1,2,4-(Me3C)3C5H2)2Th(HNMe)2] with [(h5-1,2,4-
(Me3C)3C5H2)2ThMe2],[8b] treatment of 2 with one equivalent of
[(h5-C5Me5)2ThMe2] (1) at 508C in the presence of 4-(dimethyla-
mino)pyridine (DMAP) gave the thorium imido [(h5-C5Me5)2Th= via the transition state TS, in which N(DMAP)ꢀCu and CuꢀI dis-
N(mesityl)(DMAP)] (3; Scheme 1) for which an equilibrium be-
tances are 3.559 and 2.489 ꢁ, respectively. The NꢀCu bond is
formed, whereas the CuꢀI bond is simultaneously broken, and
the resulting Iꢀ anion migrates to the Th atom to create a ThꢀI
bond. Although the formation of the intermediate INTb is ex-
ergonic with DG(298 K)=ꢀ151.3 kJmolꢀ1, the final product 6
is thermodynamically much more stable (DG(298 K)=
ꢀ191.0 kJmolꢀ1). In addition, the activation barrier to form 6
from intermediate INTb is only 12.9 kJmolꢀ1, which accounts
for the short lifetime of the non-isolable intermediate INTb,
tween imido
3
and the amido pyridyl complex [(h5-
C5Me5)2ThNH(mesityl)(h2-C,N-4-Me2NC5H3N)] (3’) exists in C6D6
solution at ambient temperature. The equilibrium constant
1
(Keq) at 298 K between 3 and 3’ determined by H NMR spec-
troscopy is 1.0. Alternatively, 3 is also accessible from the reac-
tion of [(h5-C5Me5)2ThMe2] (1) with one equivalent of mesi-
tylNH2 in the presence of DMAP (Scheme 1).
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tative. The ThꢀN(1) distances (2.168(5)–2.178(9) ꢁ) are slightly
longer than the Th=N double bond in the imido complex 3
(2.091(7) ꢁ), but much shorter than the ThꢀN single bond in
the bis(anilido) complex 2 (2.344(12) ꢁ). The Th-N-C angles of
143.9(4)-145.3(4)8 significantly deviate from linearity in compar-
ison to the Th-N-C angle observed in 3 (167.2(6)8), and are
close to the Th-N-C angle in 2 (144.4(9)8). The ThꢀX distances
of 2.727(1) ꢁ (for Cl), 2.885(2) ꢁ (for Br), and 3.120(1) ꢁ (for I)
are slightly longer than the average ThꢀX distances found in
the related bis-halido complexes [(h5-1,3-(Me3C)2C5H3)2ThCl2]
(2.632(1) ꢁ),[8b] [(h5-1,2,4-(Me3C)3C5H2)2ThCl2] (2.621(1) ꢁ),[8b] [(h5-
C5Me5)2ThBr2]
(2.800(2) ꢁ),[11]
[(h5-1,3-(Me3C)2C5H3)2ThBr2]
(2.794(1) ꢁ),[12] [(h5-1,2,4-(Me3C)3C5H2)2ThBr2] (2.785(1) ꢁ),[8c] [(h5-
C5Me5)2ThI2] (2.986(2) ꢁ)[13] and [(h5-1,3-(Me3C)2C5H3)2ThI2]
(3.035(1) ꢁ),[12] presumably due to the steric demand of the
chelating imido ligand. In contrast, the CuꢀN(1) distances of
1.874(4)–1.889(5) ꢁ are virtually identical within the statistical
uncertainties to the CuꢀN(2) distances of 1.889(10)-1.894(5) ꢁ,
whereas the N(1)-Cu-N(2) angles of 172.9(2)-175.2(2)8 deviate
slightly from linearity. Furthermore, the ThꢀCu distances of
3.140(1)–3.171(1) ꢁ are significantly shorter than the sum of
their covalent radii (3.38 ꢁ; the covalent radii of Th 2.06 ꢁ, Cu
1.32 ꢁ),[14] but they are longer than the UꢀCu distance
(3.05(1) ꢁ) in the related uranium–copper compound
[(Ph3P)Cu(m-SPh)3U(m-SPh)3Cu(PPh3)][10b] attributed to the larger
covalent radius of the Th atom (the covalent radii of Th 2.06 ꢁ,
U 1.96 ꢁ).[14] Short thorium–transition metal bond lengths are
also observed in other examples, such as [(h5-C5H5)3ThFe(h5-
Figure 3. Free-energy profile [kJmolꢀ1] for the reaction of 3+CuI ([Th]=(h5-
C5Me5)Th; and Ar=2,4,6-Me3C6H2).
and only the final product 6 was detected by NMR spectrosco-
py. Reaction of CuI was also observed for scandium imido com-
plexes, in which the Sc=N functionality coordinates to the Cu
atom of CuI, forming scandium-copper-iodide (Sc-Cu-I) hetero-
bimetallics.[5e] However, in contrast to the imido scandium
compounds,[5e] the reaction of 3 with CuI yields a heterobime-
tallic iodo-thorium-copper (I-Th-Cu) complex 6 along with
a complete cleavage of the CuꢀI bond, as a consequence of
the polarized Th+ꢀNꢀ bond. Moreover, halogen-atom ex-
change can be achieved upon addition of CuCl or CuBr to 6 to
give compounds 4 and 5, respectively, in quantitative conver-
sions (Scheme 1).
C5H5)(CO)2]
(ThꢀFe
2.940(5) ꢁ),[10a]
2.984(1) ꢁ),[10n]
[(h5-C5Me5)2Th(m-
[(h5-C5Me5)2Th(m-
PPh2)2Pt(PMe3)]
(ThꢀPt
The solid-state crystal structure of 6 is shown in Figure 4,
whereas the molecular structures of 4 and 5 are provided in
the Supporting Information. To the best of our knowledge,
complexes 4–6 represent the first structurally characterized
thorium–copper heterobimetallics, and the related uranium–
copper species, [(Ph3P)Cu(m-SPh)3U(m-SPh)3Cu(PPh3)],[10b] is the
only other reported heterobimetallic actinide–copper represen-
PPh2)2Ni(CO)2] (ThꢀNi 3.206(2) ꢁ),[10m] [(h5-C5Me5)2Th(I)Ru(h5-
C5H5)(CO)2]
(ThꢀRu
3.0277(6) ꢁ)[10]
and
[(N(o-
(NCH2PiPr2)C6H4)3)ThCo(CO)3] (ThꢀCo 3.0771(5) ꢁ).[10h] DFT stud-
ies revealed that the Wiberg bond order of ThꢀN in 6 (1.08) is
smaller than that in 3 (1.24), and the Wiberg bond order of
CuꢀN(1) is 0.28, indicating that the Cu+ atom moderates the
donation of electron density from the imido ligand to the Th4+
atom. These computations also showed some overlap between
an empty ThIV orbital and the filled CuI 3d orbitals (see the
Supporting Information for details), resulting in a computed
ThꢀCu Wiberg bond order of 0.30. Therefore, electron density
of the CuI atom is partially donated to the electropositive ThIV
atom, and therefore, the interaction between thorium and
copper is best described as a weak donor–acceptor bond
CuI!ThIV. Nevertheless, no bond critical point (BCP) was traced
between the Cu and Th atoms by a Bader analysis (see the
Supporting Information for details), as a consequence only
a weak interaction between ThIV and CuI atoms can be as-
sumed. Initial reactivity studies also confirmed this proposition,
since degradation is observed when complexes 4–6 are treated
with [(h5-C5Me5)2ThMe2] (1), forming the thorium imido 3 and
thorium methyl halido (h5-C5Me5)2Th(Me)X (X=Cl (7), Br (8), I
(9)) accompanied by the loss of methyl copper (CuMe)
(Scheme 1). The latter decomposes to copper metal (Cu) and
ethane (CH3CH3) (for details, see the Supporting Information).
In conclusion, in contrast to the reactivity of the uranium[3o,p]
and scandium[5e] imides, addition of CuX to the thorium imido
Figure 4. Molecular structure of 6 (thermal ellipsoids are drawn at the 35%
probability level).
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[(h5-C5Me5)2Th=N(mesityl)(DMAP)] (3) cleaves the CuꢀX bond
and forms the heterobimetallic thorium–copper compounds
[(h5-C5Me5)2Th(X){N(mesityl)Cu(DMAP)}] (X=Cl (4), Br (5), I (6)).
For the reaction of uranium(IV) imido complexes with copper
halides, oxidation of UIV to UV was observed,[3o,p] but this
change in oxidation states is not possible for ThIV. Nevertheless,
the reactivity difference to early transition metals can be ra-
tionalized by a more polarized Th+ꢀNꢀ bond, supporting the
notion that Th4+ belongs to the actinide metals rather than
the d transition metals.[7c] Furthermore, DFT studies attributed
the short ThꢀCu bond lengths in the thorium–copper com-
plexes to a weak donor–acceptor interaction between the elec-
tron-rich CuI and the electropositive ThIV atoms, and therefore,
the thorium–copper bimetallics are reactive compounds, as
was illustrated by their reaction with the thorium dimethyl
compound [(h5-C5Me5)2ThMe2] (1). The preparation of new acti-
nide imido complexes and the exploration of the intrinsic reac-
tivity of heterobimetallic thorium–transition metal compounds
are ongoing projects in our laboratories.
Angew. Chem. 2009, 121, 3735–3738; o) D. L. Swartz II, L. P. Spencer,
B. L. Scott, A. L. Odom, J. M. Boncella, Dalton Trans. 2010, 39, 6841–
6846; p) L. A. Seaman, S. Fortier, G. Wu, T. W. Hayton, Inorg. Chem. 2011,
50, 636–646; q) R. E. Jilek, L. P. Spencer, D. L. Kuiper, B. L. Scott, U. J. Wil-
liams, J. M. Kikkawa, E. J. Schelter, J. M. Boncella, Inorg. Chem. 2011, 50,
4235–4237; r) E. M. Matson, P. E. Fanwick, S. C. Bart, Eur. J. Inorg. Chem.
2012, 5471–5478; s) E. M. Matson, M. G. Crestani, P. E. Fanwick, S. C.
Bart, Dalton Trans. 2012, 41, 7952–7958; t) O. P. Lam, S. M. Franke, H.
Nakai, F. W. Heinemann, W. Hieringer, K. Meyer, Inorg. Chem. 2012, 51,
6190–6199; u) C. Camp, J. Pꢃcaut, M. Mazzanti, J. Am. Chem. Soc. 2013,
135, 12101–12111; v) D. M. King, F. Tuna, E. J. L. McInnes, J. McMaster,
W. Lewis, A. J. Blake, S. T. Liddle, Science 2012, 337, 717–720; w) D. M.
King, F. Tuna, E. J. L. McInnes, J. McMaster, W. Lewis, A. J. Blake, S. T.
Liddle, Nat. Chem. 2013, 5, 482–488; x) D. M. King, J. McMaster, F. Tuna,
E. J. L. McInnes, W. Lewis, A. J. Blake, S. T. Liddle, J. Am. Chem. Soc. 2014,
136, 5619–5622.
[3] For selected papers on actinide metallocenes containing terminal imido
groups, see: a) R. E. Cramer, K. Panchanatheswaran, J. W. Gilje, J. Am.
Chem. Soc. 1984, 106, 1853–1854; b) J. G. Brennan, R. A. Andersen, J.
Am. Chem. Soc. 1985, 107, 514–516; c) R. K. Rosen, R. A. Andersen,
N. M. Edelstein, J. Am. Chem. Soc. 1990, 112, 4588–4590; d) D. S. J.
Arney, C. J. Burns, D. C. Smith, J. Am. Chem. Soc. 1992, 114, 10068–
10069; e) D. S. J. Arney, C. J. Burns, J. Am. Chem. Soc. 1993, 115, 9840–
9841; f) D. S. J. Arney, C. J. Burns, J. Am. Chem. Soc. 1995, 117, 9448–
9460; g) T. Straub, W. Frank, G. J. Reiss, M. S. Eisen, J. Chem. Soc. Dalton
Trans. 1996, 2541–2546; h) B. P. Warner, B. L. Scott, C. J. Burns, Angew.
Chem. Int. Ed. 1998, 37, 959–960; Angew. Chem. 1998, 110, 1005–1007;
i) R. G. Peters, B. P. Warner, B. L. Scott, C. J. Burns, Organometallics 1999,
18, 2587–2589; j) T. Straub, A. Haskel, T. G. Neyroud, M. Kapon, M. Bo-
toshansky, M. S. Eisen, Organometallics 2001, 20, 5017–5035; k) J. L. Kip-
linger, D. E. Morris, B. L. Scott, C. J. Burns, Chem. Commun. 2002, 30–31;
l) W. J. Evans, S. A. Kozimor, J. W. Ziller, Chem. Commun. 2005, 4681–
4683; m) G. Zi, L. Jia, E. L. Werkema, M. D. Walter, J. P. Gottfriedsen, R. A.
Andersen, Organometallics 2005, 24, 4251–4262; n) G. Zi, L. L. Blosch, L.
Jia, R. A. Andersen, Organometallics 2005, 24, 4602–4612; o) C. R.
Graves, B. L. Scott, D. E. Morris, J. L. Kiplinger, J. Am. Chem. Soc. 2007,
129, 11914–11915; p) C. R. Graves, P. Yang, S. A. Kozimor, A. E. Vaughn,
D. L. Clark, S. D. Conradson, E. J. Schelter, B. L. Scott, J. D. Thompson,
P. J. Hay, D. E. Morris, J. L. Kiplinger, J. Am. Chem. Soc. 2008, 130, 5272–
5285; q) C. R. Graves, B. L. Scott, D. E. Morris, J. L. Kiplinger, Organome-
tallics 2008, 27, 3335–3337; r) C. R. Graves, A. E. Vaughn, E. J. Schelter,
B. L. Scott, J. D. Thompson, D. E. Morris, J. L. Kiplinger, Inorg. Chem.
2008, 47, 11879–11891; s) L. P. Spencer, R. L. Gdula, T. W. Hayton, B. L.
Scott, J. M. Boncella, Chem. Commun. 2008, 4986–4988; t) W. J. Evans,
C. A. Traina, J. W. Ziller, J. Am. Chem. Soc. 2009, 131, 17473–17481;
u) C. R. Graves, B. L. Scott, D. E. Morris, J. L. Kiplinger, Chem. Commun.
2009, 776–778; v) W. J. Evans, E. Montalvo, J. W. Ziller, A. G. DiPasquale,
A. L. Rheingold, Inorg. Chem. 2010, 49, 222–228; w) R. K. Thomson, T.
Cantat, B. L. Scott, D. E. Morris, E. R. Batista, J. L. Kiplinger, Nat. Chem.
2010, 2, 723–729.
Acknowledgements
This work was supported by the National Natural Science
Foundation of China (Grant No. 21472013, 21272026,
21573021), and the Deutsche Forschungsgemeinschaft (DFG)
through the Heisenberg program (WA 2513/6).
Keywords: copper
·
heterometallic complexes
·
imido
complexes · thorium · thorium–copper bond
[1] For selected reviews, see: a) M. Ephritikhine, Dalton Trans. 2006, 2501–
2516; b) E. Barnea, M. S. Eisen, Coord. Chem. Rev. 2006, 250, 855–899;
c) A. R. Fox, S. C. Bart, K. Meyer, C. C. Cummins, Nature 2008, 455, 341–
349; d) T. Andrea, M. S. Eisen, Chem. Soc. Rev. 2008, 37, 550–567; e) C. R.
Graves, J. L. Kiplinger, Chem. Commun. 2009, 3831–3853; f) T. W.
Hayton, Dalton Trans. 2010, 39, 1145–1158; g) P. L. Arnold, Chem.
Commun. 2011, 47, 9005–9010; h) T. W. Hayton, Chem. Commun. 2013,
49, 2956–2973; i) T. W. Hayton, Nat. Chem. 2013, 5, 451–452; j) G. Zi,
Sci. China Chem. 2014, 57, 1064–1072.
[2] For selected papers on uranium non-metallocenes containing terminal
imido groups, see: a) C. J. Burns, W. H. Smith, J. C. Huffman, A. P. Sattel-
berger, J. Am. Chem. Soc. 1990, 112, 3237–3239; b) D. R. Brown, R. G.
Denning, Inorg. Chem. 1996, 35, 6158–6163; c) P. Roussel, R. Boaretto,
A. J. Kingsley, N. W. Alcock, P. Scott, J. Chem. Soc. Dalton Trans. 2002,
1423–1428; d) I. Castro-Rodriguez, K. Olsen, P. Gantzel, K. Meyer, J. Am.
Chem. Soc. 2003, 125, 4565–4571; e) T. W. Hayton, J. M. Boncella, B. L.
Scott, P. D. Palmer, E. R. Batista, P. J. Hay, Science 2005, 310, 1941–1943;
f) T. W. Hayton, J. M. Boncella, B. L. Scott, E. R. Batista, P. J. Hay, J. Am.
Chem. Soc. 2006, 128, 10549–10559; g) T. W. Hayton, J. M. Boncella, B. L.
Scott, E. R. Batista, J. Am. Chem. Soc. 2006, 128, 12622–12623; h) I.
Castro-Rodrꢂguez, H. Nakai, K. Meyer, Angew. Chem. Int. Ed. 2006, 45,
2389–2392; Angew. Chem. 2006, 118, 2449–2452; i) L. P. Spencer, P.
Yang, B. L. Scott, E. R. Batista, J. M. Boncella, J. Am. Chem. Soc. 2008,
130, 2930–2931; j) S. C. Bart, C. Anthon, F. W. Heinemann, E. Bill, N. M.
Edelstein, K. Meyer, J. Am. Chem. Soc. 2008, 130, 12536–12546; k) L. P.
Spencer, E. J. Schelter, P. Yang, R. L. Gdula, B. L. Scott, J. D. Thompson,
J. L. Kiplinger, E. R. Batista, J. M. Boncella, Angew. Chem. Int. Ed. 2009, 48,
3795–3798; Angew. Chem. 2009, 121, 3853–3856; l) L. P. Spencer, P.
Yang, B. L. Scott, E. R. Batista, J. M. Boncella, Inorg. Chem. 2009, 48,
2693–2700; m) L. P. Spencer, P. Yang, B. L. Scott, E. R. Batista, J. M. Bon-
cella, Inorg. Chem. 2009, 48, 11615–11623; n) T. Cantat, C. R. Graves,
B. L. Scott, J. L. Kiplinger, Angew. Chem. Int. Ed. 2009, 48, 3681–3684;
[4] a) A. Haskel, T. Straub, M. S. Eisen, Organometallics 1996, 15, 3773–
3775; b) I. Korobkov, S. Gambarotta, G. P. A. Yap, Angew. Chem. Int. Ed.
2003, 42, 814–818; Angew. Chem. 2003, 115, 838–842; c) E. J. Schelter,
D. E. Morris, B. L. Scott, J. L. Kiplinger, Chem. Commun. 2007, 1029–
1031; d) N. L. Bell, L. Maron, P. L. Arnold, J. Am. Chem. Soc. 2015, 137,
10492–10495.
[5] Selected papers on scandium imido complexes: a) J. Scott, F. Basuli,
A. R. Fout, J. C. Huffman, D. J. Mindiola, Angew. Chem. Int. Ed. 2008, 47,
8502–8505; Angew. Chem. 2008, 120, 8630–8633; b) E. Lu, Y. Li, Y.
Chen, Chem. Commun. 2010, 46, 4469–4471; c) E. Lu, J. Chu, M. Borzov,
Y. Chen, G. Li, Chem. Commun. 2011, 47, 743–745; d) J. Chu, E. Lu, Z.
Liu, Y. Chen, X. Leng, H. Song, Angew. Chem. Int. Ed. 2011, 50, 7677–
7680; Angew. Chem. 2011, 123, 7819–7822; e) E. Lu, Q. Zhou, Y. Li, J.
Chu, Y. Chen, X. Leng, J. Sun, Chem. Commun. 2012, 48, 3403–3405;
f) Z. Jian, W. Rong, Z. Mou, Y. Pan, H. Xie, D. Cui, Chem. Commun. 2012,
48, 7516–7518; g) B. F. Wicker, H. Fan, A. K. Hickey, M. G. Crestani, J.
Scott, M. Pink, D. J. Mindiola, J. Am. Chem. Soc. 2012, 134, 20081–
20096; h) T. Chu, W. E. Piers, J. L. Dutton, M. Parvez, Organometallics
2013, 32, 1159–1165; i) J. Chu, E. Lu, Y. Chen, X. Leng, Organometallics
2013, 32, 1137–1140; j) W. Rong, J. Cheng, Z. Mou, H. Xie, D. Cui, Orga-
nometallics 2013, 32, 5523–5529; k) J. Chu, C. E. Kefalidis, L. Maron, X.
&
&
Chem. Eur. J. 2016, 22, 1 – 6
www.chemeurj.org
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Leng, Y. Chen, J. Am. Chem. Soc. 2013, 135, 8165–8168; l) J. Chu, X.
Han, C. E. Kefalidis, J. Zhou, L. Maron, X. Leng, Y. Chen, J. Am. Chem.
Soc. 2014, 136, 10894–10897.
Hou, G. Zi, D.-C. Fang, M. D. Walter, Angew. Chem. Int. Ed. 2014, 53,
11310–11314; Angew. Chem. 2014, 126, 11492–11496; f) E. Zhou, W.
Ren, G. Hou, G. Zi, D.-C. Fang, M. D. Walter, Organometallics 2015, 34,
3637–3647.
[6] Selected papers on group 4 imido complexes: a) P. J. Walsh, F. J. Hol-
lander, R. G. Bergman, J. Am. Chem. Soc. 1988, 110, 8729–8731; b) C. C.
Cummins, S. M. Baxter, P. T. Wolczanski, J. Am. Chem. Soc. 1988, 110,
8731–8733; c) J. E. Hill, R. D. Profilet, P. E. Fanwick, I. P. Rothwell, Angew.
Chem. Int. Ed. Engl. 1990, 29, 664–665; Angew. Chem. 1990, 102, 713–
715; d) H. W. Roesky, H. Voelker, M. Witt, M. Noltemeyer, Angew. Chem.
Int. Ed. Engl. 1990, 29, 669–670; Angew. Chem. 1990, 102, 712–713;
e) S. C. Dunn, A. S. Batsanov, P. Mountford, J. Chem. Soc. Chem.
Commun. 1994, 2007–2008; f) J. L. Bennett, P. T. Wolczanski, J. Am.
Chem. Soc. 1994, 116, 2179–2180; g) K. E. Meyer, P. J. Walsh, R. G. Berg-
man, J. Am. Chem. Soc. 1995, 117, 974–985; h) J. L. Polse, R. A. Ander-
sen, R. G. Bergman, J. Am. Chem. Soc. 1998, 120, 13405–13414; i) H. M.
Hoyt, F. E. Michael, R. G. Bergman, J. Am. Chem. Soc. 2004, 126, 1018–
1019; j) P. J. Tiong, A. Nova, E. Clot, P. Mountford, Chem. Commun. 2011,
47, 3147–3149; k) A. D. Schwarz, A. J. Nielson, N. Kaltsoyannis, P. Mount-
ford, Chem. Sci. 2012, 3, 819–824.
[7] Selected recent papers on the bonding of organoactinide complexes,
see: a) T. Cantat, C. R. Graves, K. C. Jantunen, C. J. Burns, B. L. Scott, E. J.
Schelter, D. E. Morris, P. J. Hay, J. L. Kiplinger, J. Am. Chem. Soc. 2008,
130, 17537–17551; b) N. Barros, D. Maynau, L. Maron, O. Eisenstein, G.
Zi, R. A. Andersen, Organometallics 2007, 26, 5059–5065; c) A. Yahia, L.
Maron, Organometallics 2009, 28, 672–679; d) J. R. Walensky, R. L.
Martin, J. W. Ziller, W. J. Evans, Inorg. Chem. 2010, 49, 10007–10012;
e) W. Ren, X. Deng, G. Zi, D.-C. Fang, Dalton Trans. 2011, 40, 9662–
9664; f) L. A. Seaman, E. A. Pedrick, T. Tsuchiya, G. Wu, E. Jakubikova,
T. W. Hayton, Angew. Chem. Int. Ed. 2013, 52, 10589–10592; Angew.
Chem. 2013, 125, 10783–10786; g) B. M. Gardner, P. A. Cleaves, C. E. Ke-
falidis, J. Fang, L. Maron, W. Lewis, A. J. Blakea, S. T. Liddle, Chem. Sci.
2014, 5, 2489–2497; h) B. Fang, G. Hou, G. Zi, D.-C. Fang, M. D. Walter,
Dalton Trans. 2015, 44, 7927–7934; i) B. Fang, L. Zhang, G. Hou, G. Zi,
D.-C. Fang, M. D. Walter, Organometallics 2015, 34, 5669–5681; j) L.
Zhang, G. Hou, G. Zi, W. Ding, M. D. Walter, J. Am. Chem. Soc. 2016, 138,
5130–5142; k) K. P. Browne, K. A. Maerzke, N. E. Travia, D. E. Morris, B. L.
Scott, N. J. Henson, P. Yang, J. L. Kiplinger, J. M. Veauthier, Inorg. Chem.
2016, 55, 4941–4950.
[9] W. A. Nugent, J. M. Mayer, Metal-Ligand Multiple Bonds, Wiley, New York,
1988.
[10] Selected examples for actinide–transition metal interactions, see: a) R. S.
Sternal, T. J. Marks, Organometallics 1987, 6, 2621–2623; b) P. Leverd,
M. Lance, M. Nierlich, J. Vigner, M. Ephritikhine, J. Chem. Soc. Dalton
Trans. 1994, 3563–3567; c) A. Bucaille, T. Le Borgne, M. Ephritikhine, J.-
C. Daran, Organometallics 2000, 19, 4912–4914; d) B. M. Gardner, D.
Patel, A. D. Cornish, J. McMaster, W. Lewis, A. J. Blake, S. T. Liddle, Chem.
Eur. J. 2011, 17, 11266–11273; e) D. Patel, F. Moro, J. McMaster, W.
Lewis, A. J. Blake, S. T. Liddle, Angew. Chem. Int. Ed. 2011, 50, 10388–
10392; Angew. Chem. 2011, 123, 10572–10576; f) M. J. Monreal, S. I.
Khan, J. L. Kiplinger, P. L. Diaconescu, Chem. Commun. 2011, 47, 9119–
9121; g) J. W. Napoline, S. J. Kraft, E. M. Matson, P. E. Fanwick, S. C. Bart,
C. M. Thomas, Inorg. Chem. 2013, 52, 12170–12177; h) A. L. Ward, W. W.
Lukens, C. C. Lu, J. Arnold, J. Am. Chem. Soc. 2014, 136, 3647–3654;
i) B. M. Gardner, J. McMaster, W. Lewis, S. T. Liddle, Chem. Commun.
2009, 2851–2853; j) B. M. Gardner, J. McMaster, F. Moro, W. Lewis, A. J.
Blake, S. T. Liddle, Chem. Eur. J. 2011, 17, 6909–6912; k) D. Patel, D. M.
King, B. M. Gardner, J. McMaster, W. Lewis, A. J. Blake, S. T. Liddle, Chem.
Commun. 2011, 47, 295–297; l) S. Fortier, J. R. Walensky, G. Wu, T. W.
Hayton, J. Am. Chem. Soc. 2011, 133, 11732–11743; m) J. M. Ritchey,
A. J. Zozulin, D. A. Wrobleski, R. R. Ryan, H. J. Wasserman, D. C. Moody,
R. T. Paine, J. Am. Chem. Soc. 1985, 107, 501–503; n) P. J. Hay, R. R. Ryan,
K. V. Salazar, D. A. Wrobleski, A. P. Sattelberger, J. Am. Chem. Soc. 1986,
108, 313–315; o) R. S. Sternal, C. P. Brock, T. J. Marks, J. Am. Chem. Soc.
1985, 107, 8270–8272; p) J. A. Hlina, J. R. Pankhurst, N. Kaltsoyannis,
P. L. Arnold, J. Am. Chem. Soc. 2016, 138, 3333–3345; and references
cited therein.
[11] D. Rabinovich, G. L. Schimek, W. T. Pennington, J. B. Nielsen, K. D. Abney,
Acta Crystallogr. C 1997, 53, 1794–1797.
[12] W. Ren, H. Song, G. Zi, M. D. Walter, Dalton Trans. 2012, 41, 5965–5973.
[13] D. Rabinovich, S. G. Bott, J. B. Nielsen, K. D. Abney, Inorg. Chim. Acta
1998, 274, 232–235.
[14] B. Cordero, V. Gꢄmez, A. E. Platero-Prats, M. Revꢃs, J. Echeverrꢂa, E. Cre-
mades, F. Barragꢅn, S. Alvarez, Dalton Trans. 2008, 2832–2838.
[8] a) W. Ren, G. Zi, D.-C. Fang, M. D. Walter, J. Am. Chem. Soc. 2011, 133,
13183–13196; b) W. Ren, G. Zi, D.-C. Fang, M. D. Walter, Chem. Eur. J.
2011, 17, 12669–12682; c) W. Ren, G. Zi, M. D. Walter, Organometallics
2012, 31, 672–679; d) W. Ren, E. Zhou, B. Fang, G. Zi, D.-C. Fang, M. D.
Walter, Chem. Sci. 2014, 5, 3165–3172; e) W. Ren, E. Zhou, B. Fang, G.
Received: July 24, 2016
Published online on && &&, 0000
Chem. Eur. J. 2016, 22, 1 – 6
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Communication
COMMUNICATION
Time for thorium! Experimental and
computational studies revealed that the
thorium–copper bond is best described
as a weak donor–acceptor interaction
between the electron-rich CuI and the
electropositive ThIV atoms (see scheme).
&
Donor–Acceptor Systems
P. Yang, E. Zhou, G. Hou, G. Zi,* W. Ding,*
M. D. Walter*
&& – &&
Experimental and Computational
Studies on the Formation of Thorium–
Copper Heterobimetallics
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Chem. Eur. J. 2016, 22, 1 – 6
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ꢀ 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ÝÝ These are not the final page numbers!