Synthesis and structure of allyl and alkynyl complexes of manganese(II) supported by a bulky β-Diketiminate ligand

Article abstract of DOI:10.1021/om049605k

Reaction of LK (L = HC(CMeNAr)₂, Ar = 2,6-iPr₂C ₆H₃) and MnCl₂(THF)_1.5 in THF unexpectedly resulted in the formation of the trinuclear complex LMn(μ-Cl)₂Mn(THF)₂(μ-Cl)₂MnL (1) in good yield. The substitution reactions of 1 with C₃H₅MgCl and PhCCLi, respectively, provided the monomeric LMnC₃H₅CTHF) (2) and the dimeric [LMn(μ-CCPh)]₂ (3) in moderate yield. Complexes 1-3 were characterized by single-crystal X-ray structural analysis. The structures show that compound 1 contains an ideal planar Mn ₃Cl₄ core and a linear Mn₃ trimer, the allyl ligand in 2 is in an η¹ mode, and there is π-interaction between the triple bond and the metal center in 3.

Full text of DOI:10.1021/om049605k

Organometallics 2004, 23, 5003-5006
5003
Syn th esis a n d Str u ctu r e of Allyl a n d Alk yn yl Com p lexes
of Ma n ga n ese(II) Su p p or ted by a Bu lk y â-Dik etim in a te
Liga n d †
J ianfang Chai, Hongping Zhu, Herbert W. Roesky,* Zhi Yang, Vojtech J ancik,
Regine Herbst-Irmer, Hans-Georg Schmidt, and Mathias Noltemeyer
Institut fu¨r Anorganische Chemie der Universita¨t Go¨ttingen,
Tammannstrasse 4, D-37077 Go¨ttingen, Germany
Received J une 3, 2004
Reaction of LK (L ) HC(CMeNAr)2, Ar ) 2,6-iPr2C6H3) and MnCl2(THF)1.5 in THF
unexpectedly resulted in the formation of the trinuclear complex LMn(µ-Cl)2Mn(THF)2(µ-
Cl)2MnL (1) in good yield. The substitution reactions of 1 with C3H5MgCl and PhCCLi,
respectively, provided the monomeric LMnC3H5(THF) (2) and the dimeric [LMn(µ-CCPh)]2
(3) in moderate yield. Complexes 1-3 were characterized by single-crystal X-ray structural
analysis. The structures show that compound 1 contains an ideal planar Mn3Cl4 core and a
linear Mn3 trimer, the allyl ligand in 2 is in an η1 mode, and there is π-interaction between
the triple bond and the metal center in 3.
In tr od u ction
some of which have novel structures and excellent
catalytic activities.4 For example, the first monomeric
Al(I) compound of composition LAl was synthesized
(L ) HC(CMeNAr)2, Ar ) 2,6-iPr2C6H3) as a stable
carbene analogue.5 Very recently we reported on the
synthesis and structure of the aluminum dihydroxide
with terminal OH groups and the first terminal hydrox-
ide containing alumoxane using the same ligand.6
Despite the impressive results obtained so far, the
utilization of such ligand systems in the synthesis of
allyl and alkynyl complexes still remains rare. To the
best of our knowledge, only few such complexes includ-
ing {HC(CtBuNAr)2}MgC3H5(THF),7 [{HC(CtBuNAr)2}-
Mg(µ-C3H5)]6,7{HC(CMeNAr′)2}B(C3H5)28(Ar′)4-MeC6H4),
and LZnCCPh9 are reported. After the interesting
results were obtained with main group elements by
taking advantage of the â-diketiminate ligands,4,5,10 we
became interested in transition metals and investigated
the synthesis and reactivity of organomanganese com-
plexes supported by such ligands. A series of manga-
nese(II) complexes including the alkyl and aryl deriva-
tives [LMn(µ-Me)]2 and LMnPh have been synthesized
Allyl and alkynyl complexes of transition metals are
important due to their synthetic methodology, theoreti-
cal implications, and the advantage of applications in
organic synthesis and catalysis.1 In addition, allyl and
alkynyl complexes are of particular interest owing to
the versatile bonding mode of the allyl and alkynyl
groups to metal centers, which can be either σ-bonded
or π-bonded.1e,2 Besides the traditional interest in
organometallic chemistry, metal-alkynyl complexes have
recently attracted special attention regarding their
potential in material science applications.3 The extended
-C≡C- unit and its potential to act as a ‘molecular
wire’ resulted in interesting electronic and structural
properties of the materials containing alkynyl groups.3
In the past few years there is increasing interest in
the â-diketiminate ligands, especially in those with
bulky aryl groups at the nitrogen, which have excellent
steric and electronic properties to stabilize unusual
coordination sites.4 A variety of main group element,
transition metal, and lanthanide complexes containing
such ligands have been synthesized and characterized,
† Dedicated to Professor Manfred Meisel on the occasion of his 65th
birthday.
* To whom correspondence should be addressed. E-mail: hroesky@
gwdg.de.
(5) Cui, C.; Roesky, H. W.; Schmidt, H.-G.; Noltemeyer, M.; Hao,
H.; Cimpoesu, F. Angew. Chem., Int. Ed. 2000, 39, 4274-4276.
(6) (a) Bai, G.; Peng, Y.; Roesky, H. W.; Li, J .; Schmidt, H.-G.;
Noltemeyer, M. Angew. Chem., Int. Ed. 2003, 42, 1132-1135. (b) Bai,
G.; Roesky, H. W.; Li, J .; Noltemeyer, M.; Schmidt, H.-G. Angew.
Chem., Int. Ed. 2003, 42, 5502-5506.
(1) (a) Davies, S. G. Organotransition Metal Chemistry: Application
to Organic Synthesis; Pergamon Press: Elmsford, NY, 1982. (b) Rosan,
A. M.; Romano, D. M. Organometallics 1990, 9, 1048-1052. (c) Hayes,
B. L.; Welker, M. E. Organometallics 1998, 17, 5534-5539. (d) Krivykh,
V. V.; Gusev, O. V.; Petrovskii, P. V.; Rybinskaya, M. I. J . Organomet.
Chem. 1989, 366, 129-145. (e) Nast, R. Coord. Chem. Rev. 1982, 47,
89-124. (f) Carriedo, G. A.; Miguel, D.; Riera, V.; Solans, X.; Font-
Altaba, M.; Coll, M. J . Organomet. Chem. 1986, 299, C43-C46.
(2) (a) Ricco, A. J .; Bakke, A. A.; J olly, W. L. Organometallics 1982,
1, 94-96. (b) Beck, W.; Niemer, B.; Wieser, M. Angew. Chem., Int. Ed.
Engl. 1993, 32, 923-949.
(3) (a) Manna, J .; J ohn, K. D.; Hopkins, M. D. Adv. Organomet.
Chem. 1995, 38, 79-154. (b) Hurst, S. K.; Ren, T. J . Organomet. Chem.
2003, 670, 188-197.
(4) Bourget-Merle, L.; Lappert, M. F.; Severn, J . R. Chem. Rev. 2002,
102, 3031-3066.
(7) Bailey, P. J .; Liddle, S. T.; Morrison, C. A.; Parsons, S. Angew.
Chem., Int. Ed. 2001, 40, 4463-4466.
(8) Qian, B.; Baek, S. W.; Smith, M. R. Polyhedron 1999, 18, 2405-
2414.
(9) Prust, J .; Hohmeister, H.; Stasch, A.; Roesky, H. W.; Magull, J .;
Alexopoulos, E.; Uso´n, I.; Schmidt, H.-G.; Noltemeyer, M. Eur. J . Inorg.
Chem. 2002, 2156-2162.
(10) Selected samples: (a) J ancik, V.; Peng, Y.; Roesky, H. W.; Li,
J .; Neculai, D.; Neculai, A. M.; Herbst-Irmer, R. J . Am. Chem. Soc.
2003, 125, 1452-1453. (b) Ding, Y.; Ma, Q.; Uso´n, I.; Roesky, H. W.;
Noltemeyer, M.; Schmidt, H.-G. J . Am. Chem. Soc. 2002, 124, 8542-
8543. (c) Cui, C.; Ko¨pke, S.; Herbst-Irmer, R.; Roesky, H. W.; Nolte-
meyer, M.; Schmidt, H.-G.; Wrackmeyer, B. J . Am. Chem. Soc. 2001,
123, 9091-9098.
10.1021/om049605k CCC: $27.50 © 2004 American Chemical Society
Publication on Web 09/01/2004

5004 Organometallics, Vol. 23, No. 21, 2004
Chai et al.
Sch em e 1
Sch em e 2
F igu r e 1. Molecular structure of 1 (50% probability
thermal ellipsoids). Hydrogen atoms are omitted for clarity.
and well characterized.11 Herein we report on the
synthesis and structure of the trimeric complex LMn-
(µ-Cl)2Mn(THF)2(µ-Cl)2MnL (1) containing the same
bulky â-diketiminate ligand and its allyl and alkynyl
derivatives LMnC3H5(THF) (2) and [LMn(µ-CCPh)]2 (3).
Resu lts a n d Discu ssion
Syn th esis of Com p ou n d s 1-3. We have reported
the reaction of LK (L ) HC(CMeNAr)2, Ar ) 2,6-
iPr2C6H3) and MnCl2 in diethyl ether to afford the
dimeric complex [LMn(µ-Cl)]2.11c However, the similar
reaction of LK and MnCl2(THF)1.5 in THF unexpectedly
resulted in the formation of the trimer LMn(µ-Cl)2Mn-
(THF)2(µ-Cl)2MnL (1) in good yield, although a ratio of
1: 1 of the starting materials was employed (Scheme 1).
The addition of C3H5MgCl and PhCCLi, respectively,
to 1 in toluene at low temperature smoothly provided
the monomeric compound LMnC3H5(THF) (2) and the
dimer [LMn(µ-CCPh)]2 (3) in moderate yield (Scheme
2). The efforts to identify other species were unsuccess-
ful. Compared with the metathesis reaction of the
dimers [LMn(µ-Cl)]2 and [LMn(µ-I)]2 with MeLi and
PhLi,11 the reactions of 1 with C3H5MgCl and PhCCLi
resulted in easily available products that can be purified
by recrystallization.
F igu r e 2. Molecular structure of 2 (50% probability
thermal ellipsoids). Hydrogen atoms are omitted for clarity.
Complexes 1-3 are yellow crystalline solids and
soluble in THF. Compounds 2 and 3 are sensitive to air
and moisture and have a much better solubility than 1.
These complexes were characterized by elemental analy-
ses, EI-MS, and IR. EI-MS of 1 shows that the molecular
ion peak is silent; rather, [LMnCl]+ is observed as the
most intense ion at m/z 507. In the EI-MS of 2,
[LMnC3H5]+ appears at m/z 537 (8%) without the
coordinated THF, followed by m/z 472 [LMn]+ as the
most intense peak. Interestingly, the molecular ion [M]+
at m/z 1146 in the mass spectrum of 3 can be seen albeit
with very low intensity (1%), followed by [1/2M]+ m/z
573 (40%) and [LMn - H]+ m/z 471 (100%). The
vibration for the bridging -CtC- group in the IR
F igu r e 3. Molecular structure of 3 (50% probability
thermal ellipsoids). Hydrogen atoms are omitted for clarity.
spectrum of 3 appears at 2034 cm-1, which is consistent
with the decrease of the bond strength of the CtC unit
due to the π-interaction with the metal center.
X-r a y Solid -Sta te Str u ctu r a l An a lysis. Complexes
1-3 were characterized by single-crystal X-ray diffrac-
tion. The structures of 1-3 are shown in Figures 1-3,
respectively. Crystallographic data are given in Table
1, and selected bond lengths and angles in Table 2.
(11) (a) Chai, J .; Zhu, H.; Most, K.; Roesky, H. W.; Vidovic, D.;
Schmidt, H.-G.; Noltemeyer, M. Eur. J . Inorg. Chem. 2003, 4332-4337.
(b) Chai, J .; Zhu, H.; Fan, H.; Roesky, H. W.; Magull, J . Organo-
metallics 2004, 23, 1177-1179. (c) Chai, J .; Zhu, H.; Roesky, H. W.;
He, C.; Schmidt, H.-G.; Noltemeyer, M. Organometallics 2004, in press.

Allyl and Alkynyl Complexes of Mn(II)
Organometallics, Vol. 23, No. 21, 2004 5005
Ta ble 1. Cr ysta llogr a p h ic Da ta for Com p lexes 1-3
1 incl. 4 THF
2
1/2 3
formula
fw
C
82H130Cl4Mn3N4O6
C36H54MnN2O
585.75
C37H46MnN2
573.70
1574.52
T (K)
133(2)
133(2)
100(2)
λ (Å)
0.71073
monoclinic
C2/m
17.238(3)
18.411(3)
14.729(2)
90.00
113.947(13)
90.00
4272.3(12)
2
1.224
0.612
1682
0.30 × 0.20 × 0.20
3.02-49.60
22 430
3785 (R(int) ) 0.1105)
3785/0/214
1.028
0.0777, 0.2045
0.1171, 0.2295
1.021/-0.646
0.71073
triclinic
P1h
9.034(2)
12.177(4)
15.95(2)
87.22(2)
77.909(16)
89.24(2)
1713.9(7)
2
1.54178
monoclinic
P2(1)/n
14.010(1)
13.257(1)
17.697(1)
90.00
98.59(1)
90.00
3250(1)
4
cryst syst
space group
a (Å)
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
Z
Dcalcd (g cm-3
)
1.135
0.413
634
1.172
3.483
1228
µ (mm-1
F(000)
)
cryst size (mm3)
0.30 × 0.30 × 0.30
3.34-49.44
18 432
5810 (R(int) ) 0.0417)
5810/0/379
1.036
0.0341, 0.0772
0.0487, 0.0814
0.380/-0.220
0.30 × 0.20 × 0.10
7.52-118.92
15 989
4673 (R(int) ) 0.0458)
4673/0/375
1.049
0.0356, 0.0803
0.0503, 0.0860
0.441/-0.251
2θ range (deg)
no. of rflns collected
no. of indep rflns
no. of data/restraints/params
goodness-of-fit, F2
R1, wR2 [I > 2σ(I)]
R1, wR2 (all data)
largest diff peak/hole (e Å-3
)
Ta ble 2. Selected Bon d Len gth s (Å) a n d Bon d
(µ-Cl)]2, while the bridging Mn-Cl distances are about
0.07 Å longer.11c
An gles (d eg) for Com p ou n d s 1-3
Compound 2 is a monomeric species in which the allyl
ligand is bound to the four coordinate manganese center
in an η1 arrangement. To the best of our knowledge, 2
is the first structurally characterized allyl-manganese
complex in an η1 mode of the ligand. The metal center
is of distorted tetrahedral geometry surrounded by the
allyl group, a THF molecule, and the chelating ligand.
The backbone of the chelating ligand is nearly planar,
and the manganese atom is out of this plane (0.53 Å),
which is nearly in orthogonal position with the plane
formed by Mn(1), C(6), and O(1). The Mn-C bond length
(2.13 Å) is in the normal range of the Mn-C single bond
and a little shorter than those in manganese complexes
with allyl groups in η3 mode.12 The large difference
between the distances of C(7)-C(8) (1.31 Å) and C(6)-
C(7) (1.44 Å) shows that there is no obvious delocaliza-
tion of π-electrons of the allyl group. The distance
between Mn(1) and C(8) (3.88 Å) does not support any
bonding interaction. Interestingly, both the N-Mn-N
angle (92.2°) and the Mn-N bond lengths (av 2.09 Å)
in 2 are larger than the corresponding ones in 1 (91.3°
and 2.08 Å, respectively) due to the different trans effect.
The solid-state structure of 3 (Figure 3) reveals a
dimer formed by two bridging phenylethynyl groups,
which is best described by assuming that Mn(1)-C(30)
is a σ-bond and that the two monomer units are linked
together through π-bonding by donation of π-electron
density of one CtC bond to the empty orbital of the
other metal center. To the best of our knowledge,
compound 3 is the first structurally characterized
dinuclear manganese complex containing bridging
alkynyl groups. Similar to complexes 1 and 2, the
manganese atom is out of the chelating ligand plane
(0.47 Å). The central core contains an ideal planar four-
Compound 1
Mn(1)-N(1)
Mn(1)-N(1A)
Mn(1)-Cl(1)
Mn(1)-Cl(2)
Mn(2)-Cl(1)
Mn(2)-Cl(2)
Mn(2)-O(4)
Mn(1)-Mn(2)
2.077(5)
2.077(4)
2.391(2)
2.412(2)
2.576(2)
2.527(2)
2.200(6)
3.564
N(1)-Mn(1)-N(1A)
N(1)-Mn(1)-Cl(1)
N(1)-Mn(1)-Cl(2)
Cl(1)-Mn(1)-Cl(2)
O(4)-Mn(2)-O(4A)
O(4)-Mn(2)-Cl(2)
O(4)-Mn(2)-Cl(1)
Cl(1)-Mn(2)-Cl(2)
91.3(2)
120.65(13)
117.80(12)
91.36(7)
180.0
90.0
90.0
84.65(6)
Compound 2
Mn(1)-N(1)
Mn(1)-N(2)
Mn(1)-C(6)
Mn(1)-O(1)
C(7)-C(8)
2.092(2)
2.095(2)
2.132(2)
2.163(1)
1.305(4)
1.444(3)
N(1)-Mn(1)-N(2)
N(1)-Mn(1)-C(6)
N(2)-Mn(1)-C(6)
N(1)-Mn(1)-O(1)
N(2)-Mn(1)-O(1)
C(6)-Mn(1)-O(1)
92.19(6)
123.58(7)
123.35(8)
102.62(6)
101.77(6)
109.60(8)
C(6)-C(7)
Compound 3
Mn(1)-N(1)
Mn(1)-N(2)
Mn(1)-C(30)
Mn(1)-C(30A)
Mn(1A)-C(30)
2.091(2) N(1)-Mn(1)-N(2)
2.105(2) N(1)-Mn(1)-C(30)
2.298(2) N(2)-Mn(1)-C(30)
2.133(2) C(30)-Mn(1)-C(30A)
2.133(2) N(1)-Mn(1)-C(30A)
89.60(7)
119.51(8)
120.78(7)
90.55(8)
116.68(8)
122.72(8)
Mn(1)-Mn(1A) 3.120(1) N(2)-Mn(1)-C(30A)
C(30)-C(31)
1.226(3) Mn(1A)-C(30)-C(31) 177.17(2)
Compound 1 crystallizes in the monoclinic space
group C2/m with two molecules per unit cell. The
molecule consists of a linear trimer with four bridging
chlorine atoms and two chelating ligands adopting a
symmetric structure, which, in fact, is one MnCl2(THF)2
molecule captured by the [LMn(µ-Cl)]2 dimer. The
central Mn(2) atom has a distorted octahedral coordina-
tion sphere with two THF molecules in trans position,
while the two remaining manganese atoms achieve a
distorted tetrahedral geometry. The internal Cl(1)-Mn-
(2)-Cl(2) and Mn-Cl-Mn angles (84.7° and av 92.0°,
respectively) result in the Mn-Mn distances (3.56 Å),
which are longer than the distance (3.28 Å) observed in
[LMn(µ-Cl)]2.11c The two bridging Mn2Cl2 rings are
ideally coplanar, which bisect and are perpendicular
(90.0°) to the two chelating ligands around them. The
Mn-N bond lengths compare well with those in [LMn-
(12) (a) Liehr, G.; Seibold, H.-J .; Behrens, H. J . Organomet. Chem.
1983, 248, 351-355. (b) Lenhert, P. G.; Lukehart, C. M.; Srinivasan,
K. J . Am. Chem. Soc. 1984, 106, 124-130. (c) Brisdon, B. J .; Edwards,
D. A.; White, J . W.; Drew, M. G. B. J . Chem. Soc., Dalton Trans. 1980,
2129-2137.

5006 Organometallics, Vol. 23, No. 21, 2004
Chai et al.
(81%). Mp: >400 °C. Anal. Calcd for C66H98Cl4Mn3N4O2
(1286.51): C, 61.56; H, 7.62; N, 4.35. Found: C, 61.55; H, 7.49;
N, 4.21. EI-MS: m/z (%) 507 (100) [LMnCl]+. IR (Nujol mull,
cm-1): ν˜ 1525 (m), 1400 (w), 1316 (s), 1292 (w), 1263 (s), 1230
(w), 1176 (w), 1100 (s), 1098 (m), 1075 (m), 1056 (m), 1022 (s),
934 (w), 852 (w), 794 (s), 758 (m), 721 (w), 636 (w), 527 (w),
468 (w), 452 (w).
membered Mn2C2 ring, which bisects and is perpen-
dicular (90.8°) to the two chelating ligands around it.
The distance between the two manganese atoms (3.12
Å) is beyond a Mn-Mn bonding range and is signifi-
cantly longer than those in dimeric manganese alkyl
complexes [LMn(µ-Me)]211b (2.81 Å) and [Mn(CH2SiMe3)-
(PMe3)(µ-CH2SiMe3)]213 (2.77 Å). This indicates that the
bridge bonding in 3 is different from those in other
dimeric species. The carbon-carbon triple bond length
(1.23 Å) is longer than the accepted average value of
1.21 Å, reflecting the π-interaction between the triple
bond and the metal center. Similar bond lengths are
observed in [CuCl(η2-PhCCMn(CO)3(dppe))]14 (1.23 Å)
and {Cu[η2-tBuCCMn(CO)3(dppe)]2}PF61f (1.24 Å) hav-
ing alkynyl-manganese groups π-bonded to the copper.
Despite the π-interaction between the triple bond and
the metal center in 3, the Mn(1A)-C(30)-C(31) unit
remains almost linear (177.0°). The Mn-C bond lengths
(av 2.22 Å) are significantly longer than those (1.90-
2.08 Å) in manganese complexes with terminal alkynyl
groups.15
LMn C3H5(THF ) (2). C3H5MgCl (1.1 mL, 2.0 M in THF, 2.2
mmol) was added to a suspension of 1 (0.64 g, 0.5 mmol) in
toluene (20 mL) at -78 °C. The mixture was allowed to warm
to room temperature and stirred for 14 h. All volatiles were
removed in a vacuum, and the residue was extracted with
hexane (2 × 15 mL). The yellow solution was concentrated to
ca. 15 mL and kept at 4 °C for 48 h to give yellow crystals. No
other species was isolated. The crystals were collected by
filtration, and the filtrate was concentrated and kept at -26
°C for 7 days to give additional crystals. Total yield: 0.25 g
(43%). Mp: >173 °C (dec). Anal. Calcd for C36H54MnN2O
(585.75): C, 73.75; H, 9.22; N, 4.78. Found: C, 74.13; H, 8.96;
N, 4.64. EI-MS: m/z (%) 513 (8) [M - THF]+, 472 (100) [LMn]+.
IR (Nujol mull, cm-1): ν˜ 1653 (w), 1521 (m), 1401 (m), 1317
(m), 1262 (s), 1175 (w), 1098 (s), 1021 (m), 933 (w), 847 (w),
794 (m), 760 (w), 738 (w), 722 (m), 693 (w), 663 (w).
[LMn (µ-CCP h )]2 (3). PhCCLi (2.2 mL, 1.0 M in THF, 2.2
mmol) was added to a suspension of 1 (0.64 g, 0.5 mmol) in
toluene (20 mL) at -78 °C. The mixture was allowed to warm
to room temperature and stirred for 14 h. All volatiles were
removed in a vacuum, and the residue was extracted with
hexane (2 × 15 mL). The yellow solution was concentrated to
ca. 15 mL and kept at 4 °C for 48 h to give yellow crystals. No
other species was isolated. The crystals were collected by
filtration, and the filtrate was concentrated and kept at -26
°C for 4 days to give additional crystals. Total yield: 0.32 g
(56%). Mp: >170 °C (dec). Anal. Calcd for C74H92Mn2N4
(1147.4): C, 77.39; H, 8.02; N, 4.88. Found: C, 77.13; H, 8.46;
N, 4.72. EI-MS: m/z (%) 1146 (1) [M]+, 573 (40) [1/2M]+, 471
(100) [LMn - H]+. IR (Nujol mull, cm-1): ν˜ 2034 (w), 1524
(m), 1317 (m), 1260 (s), 1177 (w), 1098 (s), 1056 (m), 1021 (s),
931 (w), 865 (w), 756 (w), 721 (m).
Con clu sion
In summary, the trimeric compound LMn(µ-Cl)2Mn-
(THF)2(µ-Cl)2MnL (1) (L ) HC(CMeNAr)2, Ar ) 2,6-
iPr2C6H3) was obtained from the reaction of LK and
MnCl2(THF)1.5 when THF was employed as solvent. The
substitution reactions of 1 with C3H5MgCl and PhCCLi
afforded the monomeric η1-allyl compound 2 and the
dimeric alkynyl compound 3, respectively. The success-
ful isolation of complexes 2 and 3 proves again that
â-diketiminate ligands are ideal to prepare organo-
manganese complexes.
Exp er im en ta l Section
X-r a y Cr ysta llogr a p h y. Crystallographic data for 1 and
2 were collected on a Stoe IPDS II-array detector system with
graphite-monochromated Mo KR radiation (λ ) 0.71073 Å) and
for 3 on a Bruker three-circle diffractometer equipped with a
SMART 6000 CCD detector using Cu KR radiation (λ )
1.54178 Å). All structures were solved by direct methods
Gen er a l P r oced u r es. All reactions were performed using
standard Schlenk and drybox techniques. Solvents were ap-
propriately dried and distilled under dinitrogen prior to use.
Elemental analyses were performed by the Analytisches Labor
des Instituts fu¨r Anorganische Chemie der Universita¨t Go¨t-
tingen. Mass spectra were obtained on a Finnigan Mat 8230
instrument. IR spectra were recorded on a Bio-Rad Digilab
FTS-7 spectrometer as Nujol mulls between KBr plates. LK11a
2
(SHELXS-97)17 and refined against F using SHELXL-97.18
All non-hydrogen atoms were refined anisotropically. The
hydrogen atoms were included at geometrically calculated
positions and refined using a riding model.
16
(L ) HC(CMeNAr)2, Ar ) 2,6-iPr2C6H3) and MnCl2(THF)1.5
were synthesized as described in the literature.
LMn (µ-Cl)2Mn (THF )2(µ-Cl)2Mn L (1). LK (0.91 g, 2 mmol)
in THF (15 mL) was added to a suspension of MnCl2(THF)1.5
(0.70 g, 3 mmol) in THF (40 mL) at -78 °C. The mixture was
warmed to room temperature and stirred for 14 h. The
precipitate was removed by filtration. The solution was
concentrated to ca. 10 mL and kept at 4 °C for 24 h to give
yellow crystals. The crystals were collected by filtration, and
the mother liquid was concentrated to ca. 5 mL and kept at
-26 °C for 24 h to give additional crystals. Total yield: 1.28 g
Ack n ow led gm en t. We are grateful to the Deutsche
Forschungsgemeinschaft, the Fonds der Chemischen
Industrie, and the Go¨ttinger Akademie der Wissen-
schaften for support of this work.
Su p p or tin g In for m a tion Ava ila ble: X-ray structural
information for complexes 1-3. This material is available free
of charge via the Internet at http://pubs.acs.org.
(13) Davies, J . I.; Howard, C. G.; Skapski, A. C.; Wilkinson, G. J .
Chem. Soc., Chem. Commun. 1982, 1077-1078.
OM049605K
(14) Solans, X.; Solans, J .; Miravitlles, C.; Miguel, D.; Riera, V.;
Rubio-Gonzalez, J . M. Acta Crystallogr. C 1986, 42, 975-977.
(15) Riese, U.; Neumu¨ller, B.; Faza, N.; Massa, W.; Dehnicke, K. Z.
Anorg. Allg. Chem. 1997, 623, 351-356, and references therein.
(16) Kern, R. J . J . Inorg. Nucl. Chem. 1962, 24, 1105-1109.
(17) Sheldrick, G. M. Acta Crystallogr. Sect. A 1990, 46, 467-473.
(18) Sheldrick, G. M. SHELXL-97, Program for Crystal Structure
Refinement; Universita¨t Go¨ttingen, 1997.