Synthesis and structural studies of some gold(I) complexes containing selenoureato ligands

Article abstract of DOI:10.1016/j.tet.2012.09.023

N,N-Diethyl-N′-4-nitrobenzoylselenourea (HL^Se) reacts with the mono- and dinuclear phosphine gold(I) chloro complexes [AuCl(PR ₃)] (R=Ph, o-tol, Et) and [Au₂Cl₂(μ-P-P)] (P-P=dppm, dppe, dppp, dppb, dppf) in the presence of base to give gold(I) phosphine selenoureato complexes [Au(L^Se)(PR₃)] [R=Ph (1), o-tol (2), Et (3)], [Au₂(L^Se)₂(μ-P-P)] [P-P=dppm (4), dppe (5), dppp (6), dppb (7), dppf (8)] in excellent yields. The compounds were fully characterised by spectroscopic methods and, in the case of compounds 1, 5 and 8, by single crystal X-ray diffraction. The compounds consist of a gold atom bound in linear fashion to the phosphine ligand and the selenium atom from the deprotonated acylselenourea. These complexes thus represent the first examples of acylselenoureato metal compounds in which the ligands do not adopt the typical O,Se chelating mode but rather coordinate to the metal only through the selenium atom.

Full text of DOI:10.1016/j.tet.2012.09.023

Tetrahedron 68 (2012) 10586e10591
Contents lists available at SciVerse ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Synthesis and structural studies of some gold(I) complexes containing
selenoureato ligands
a
b
b
a,
*
€
Anja Molter , Jorg Rust , Christian W. Lehmann , Fabian Mohr
a
€
Fachbereich CdAnorganische Chemie, Bergische Universitat Wuppertal, Gaussstr. 20, 42119 Wuppertal, Germany
b
€
€
Max-Planck Institut fur Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mulheim an der Ruhr, Germany
a r t i c l e i n f o
a b s t r a c t
N,N-Diethyl-N0-4-nitrobenzoylselenourea (HLSe) reacts with the mono- and dinuclear phosphine gold(I)
Article history:
Received 9 July 2012
Received in revised form 28 August 2012
Accepted 4 September 2012
Available online 11 September 2012
chloro complexes [AuCl(PR3)] (R¼Ph, o-tol, Et) and [Au2Cl2( -P-P)] (P-P¼dppm, dppe, dppp, dppb, dppf)
m
in the presence of base to give gold(I) phosphine selenoureato complexes [Au(LSe)(PR3)] [R¼Ph (1), o-tol
(2), Et (3)], [Au2(LSe)2(
m
-P-P)] [P-P¼dppm (4), dppe (5), dppp (6), dppb (7), dppf (8)] in excellent yields.
The compounds were fully characterised by spectroscopic methods and, in the case of compounds 1, 5
and 8, by single crystal X-ray diffraction. The compounds consist of a gold atom bound in linear fashion to
the phosphine ligand and the selenium atom from the deprotonated acylselenourea. These complexes
thus represent the first examples of acylselenoureato metal compounds in which the ligands do not
adopt the typical O,Se chelating mode but rather coordinate to the metal only through the selenium
atom.
Keywords:
Acylselenourea
Gold complexes
Softesoft interactions
X-ray crystal structure
Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction
It is noteworthy that for the coinage metals (Cu, Ag and Au) only
bis(selenoureato) chelate complexes with copper(II) are
Acylselenoureas of the type ArC(O)NHC(Se)NR2 derived from
the reaction of an aromatic acid chloride with KSeCN and sub-
sequent addition of a secondary amine have been known since
1937.1 Modified synthetic methods and organic transformations of
these (or structurally similar) compounds have been reported since
then.2e9 However, the main focus has been directed towards the
use of acylselenoureas as chelating ligands for metal compounds
with applications in analytical chemistry, metal extraction and,
more recently, as single-source precursors for metal selenide
nanomaterials.10e17 In general, deprotonated acylselenoureas co-
ordinate to a metal centre via both the selenium and oxygen atoms,
forming metallacyclic rings (Fig. 1). Numerous examples of such
types of compounds with metals including Tl(I), Cd(II), In(III), Zn(II),
Ni(II), Co(III), Pb(II), Pd(II) Pt(II) have been reported and many have
also been structurally characterised.2,14e16,18e28
known.20,27,29 Given the fact that acylselenoureas contain one hard
(oxygen) and one soft (selenium) donor atom, the reaction with
a soft metal centre may lead to a compound in which only the se-
lenium is bound to the metal (Fig. 2). In this case however, the
stabilizing chelate effect of the selenoureato unit would be lost. It is
worth noting, that a gold(I) complex containing an N-seleno-
carbamoyl benzamidine, which can be considered as a nitrogen
analogue of a selenourea, was recently isolated and structurally
characterized.30 In this compound the neutral ligand acts as a Se-
R2N
M
N
Ar
Se
O
M = soft metal
Et2N
N
Ph
Se HN
Au
Cl
Me
Fig. 1. Schematic representation of a selenoureato metal chelate complex.
* Corresponding author. E-mail address: fmohr@uni-wuppertal.de (F. Mohr).
Fig. 2. Schematic representation of a selenoureato complex with a soft metal centre
(top) as well as the known gold(I) complex containing a neutral N-selenocarbamoyl
benzamidine (bottom).
0040-4020/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.tet.2012.09.023

A. Molter et al. / Tetrahedron 68 (2012) 10586e10591
10587
donor ligand (Fig. 2). There are to date however no examples in the
literature of gold complexes containing anionic selenourea
derivatives.31
Given our past interest in the chemistry of transition metal
compounds with chalcogen ligands and the coordination chemistry
of organic selenium species,2,30e48 we wished to study the re-
activity of selenoureas with a soft metal centre (gold) to see if either
chelate type complexes are formed or if the selenoureato ligand
binds only via the selenium atom. The results of this investigation
are reported here.
ligands, both CeS and CeO signals experience a shift of ca. 10 ppm
when compared to the free ligand. This suggests that the chemical
environment about the CeO unit does not change significantly
upon coordination and thus the acylselenourea is likely to be bound
to gold solely via the selenium atom. Indeed this could be un-
ambiguously confirmed by X-ray crystallographic studies of com-
plexes 1, 5 and 8. The molecular structures are shown in Figs. 3e5,
selected bond distances and angles are collected in Table 1.
2. Results and discussion
N,N-Diethyl-N0-4-nitrobenzoylselenourea (HLSe) reacts with the
phosphine gold(I) chloro complexes [AuCl(PR3)] (R¼Ph, o-tol, Et)
and [Au2Cl2(
m
-P-P)] (P-P¼dppm, dppe, dppp, dppb, dppf) in the
presence of base to give the air- and light-stable gold(I) phosphine
selenoureato complexes [Au(LSe)(PR3)] [R¼Ph (1), o-tol (2), Et (3)],
[Au2(LSe)2(
dppf (8)] in excellent yields (Scheme 1).
m
-P-P)] [P-P¼dppm (4), dppe (5), dppp (6), dppb (7),
The new compounds were fully characterized by NMR spec-
troscopy, IR spectroscopy and elemental analysis. The solid-state
structures of some compounds were also determined by X-ray
crystallography. Most diagnostically, apart from the disappearance
of the NeH signal in the proton NMR spectra, are the changes in
chemical shifts of the signals in the 31P and 77Se NMR spectra. In the
case of the 31P NMR shifts, the singlet resonances are moved several
ppm downfield compared to those of the parent chloro complexes.
Furthermore, upon deprotonation and coordination to gold the 77Se
NMR signal is shifted from 502 ppm in HLSe to about 200 pm in the
complexes. Although there is not much 31P and 77Se NMR data
reported for phosphine gold(I) complexes containing anionic se-
lenium ligands, the trend observed here is consistent with what we
have observed previously in gold(I) complexes containing depro-
tonated selenosemicarbazone ligands.46 Here too, deprotonation
and coordination to gold causes an upfield shift by about 300 pm.
While these data do not allow us to unambiguously identify the
coordination mode (chelate or monodentate via Se) of the sele-
noureato unit, comparison of the 13C NMR chemical shifts of the
CeO and CeSe signals gives more information. The signal of the
CeO carbon atom experiences a much smaller (ca. 5 ppm) shift
upon coordination of the acylselenourea unit when compared to
HLSe. In contrast, that of the CeSe carbon atom shifts by about
12 ppm. In complexes where the selenoureas act as chelating
Fig. 3. Molecular structure of complex 1. Hydrogen atoms have been omitted for
clarity.
Each compound consists of a gold atom bound, as expected, in
linear fashion to a phosphorus atom from the phosphine ligand and
theseleniumatomfrom thedeprotonatedacylselenoureamoiety. The
AueP and AueSe bond distances and angles are within the range
typically observed for such compounds.31 The carbonyl oxygen atom
ꢀ
is around 3.4 A away from the gold atom (sum of the Van der Waals
Scheme 1.

10588
A. Molter et al. / Tetrahedron 68 (2012) 10586e10591
ꢀ
radii¼3.2 A), too far for any significant interactions to occur. In the
structurally related gold(I) chloro compound containing a neutral, S-
bonded acylthioureato ligand [AuCl{PhC(O)NHC(S)NEt2}] the AueO
49
ꢀ
separation is with 4.2 A even greater. Comparison of the bond
lengths in the ligand backbone also confirms that the degree of de-
localization is considerably less than what is usually found in the
chelating coordination mode. The CeO bond lengths do not change
ꢀ
significantly upon coordination (1.22 vs 1.24 A), whereas the CeSe
ꢀ
distance increases considerably (1.82e1.92 A). This suggests that the
CeSe bond has more single bond character and the CeO bond more
double bond character. The lack of delocalization is further confirmed
by the CeN bond lengths in the ligand backbone. Whilst in chelate
complexes these are almost identical, there is an alternating long,
short, long pattern observed in these three complexes. Overall, it can
be seen that the deprotonated acylselenoureato ligand coordinates to
the gold only via the selenium atom and that the delocalization in the
ligandbackboneissignificantlylessthaninthechelatingcoordination
mode. These compounds thus represent the first examples of metal
compounds containing anionic acylselenoureato ligands, which do
not display the chelating coordination mode, which is so typical for
this familyofligands. Applicationsof these compoundsinmedicineas
anti-malaria and anti-tumour agents are currently being investigated
by us and results will be reported once they become available.
Fig. 4. Molecular structure of complex 5. Hydrogen atoms have been omitted for
clarity.
3. Experimental
3.1. General
1H, 13C{1H}, 31P{1H} and 77Se NMR spectra were recorded on
a Bruker Avance ARX 400 (400 MHz) or Bruker Avance II 600
(600 MHz) spectrometer. Chemical shifts are quoted relative to ex-
ternal SiMe4 (1H, 13C), 85% H3PO4 (31P) and Me2Se (77Se). Elemental
analyses were performed by staff of the micro-analytical laboratory
of the University of Wuppertal. Reactions were typically carried out
under ambient conditions, without protection from air or moisture.
Commercial solvents (HPLC grade) and reagents were used as re-
ceived. The phosphine gold(I) chloro complexes were readily acces-
sible from the reaction of [AuCl(tht)]50 (tht¼tetrahydrothiophene)
with the appropriate phosphines in CH2Cl2.
3.2. N,N-Diethyl-N0-4-nitrobenzoylselenourea (HLSe
)
To a suspension of KSeCN (2.88 g, 20 mmol) and PEG-400
(0.28 mL) in CH2Cl2 (10 mL) was added a solution of 4-nitro-
benzoylchloride (3.71 g, 20 mmol) in CH2Cl2 (20 mL). After ca.
15 min at room temperature Et2NH (2.07 mL, 20 mmol) was added,
and the resulting mixture was stirred for 1 h protected from light.
The red-orange mixture was filtered and the filtrate subsequently
evaporated to dryness. The resulting solid was recrystallised from
EtOH to give 2.29 g (35%) orange crystals. 1H NMR (400 MHz,
Fig. 5. Molecular structure of complex 8. Hydrogen atoms have been omitted for
clarity.
Table 1
Selected bond distances and angles in complexes 1, 3 and 8
CDCl3):
d
¼1.33 (t, J¼7.1 Hz, 3H, NCH2CH3), 1.41 (t, J¼6.3 Hz, 3H,
[Au(LSe)(PPh3)] [Au2(LSe)2(
m
-dppe)] [Au2(LSe)2(
m-dppf)]
NCH2CH3), 3.60 (br s, 2H, NCH2CH3), 4.14 (br s, 2H, NCH2CH3), 8.03
(d, J¼8.2 Hz, 2H, H-2), 8.32 (d, J¼8.2 Hz, 2H, H-3), 8.65 (br s, 1H,
(1)
(5)
(8)
NH) ppm. 13C{1H} NMR (101 MHz, CDCl3):
d
¼11.6 (NCH2CH3), 12.9
Bond distances
PeAu
AueSe
SeeC
OeC
(Se)CeN(C(O))
(O)CeN
(O)CeC(p-C6H4NO2) 1.503(6)
2.2683(10)
2.4112(4)
1.927(4)
1.240(6)
1.306(6)
1.337(6)
2.262(2)
2.4170(9)
1.968(8)
1.216(10)
1.305(12)
1.354(13)
1.530(12)
2.2622(12)
2.4125(6)
1.929(6)
1.216(7)
1.318(7)
1.367(7)
1.512(8)
(NCH2CH3), 48.6 (NCH2CH3), 51.4 (NCH2CH3), 124.1 (C-3), 129.1 (C-
2), 137.9 (C-1), 150.4 (C-4), 160.4 (C]O), 179.8 (C]Se) ppm. 77Se
NMR (76 MHz, CDCl3):
d
¼502 ppm. IR (KBr disk)
n: 1347 (s, NO2),
1526 (s, NO2),1649 (s, C]O amido urea), 2933 (w, Csp3 eH), 2975 (w,
Csp3 eH), 3055 (w, Csp2 eH), 3289 (m, NeH) cmꢀ1. Elemental anal-
ysis calcd (%) for C12H15N3O3Se (328.23 g/mol): C 43.91, H 4.61, N
12.80; found C 43.22, H 4.49, N 13.02.
Bond angles
PeAueSe
AueSeeC
SeeCeN(C(O))
SeeCeNeC(O)
OeCeNeC(Se)
175.31(3)
101.84(13)
124.5(3)
38.2(6)
172.15(6)
94.7(2)
120.9(6)
44(1)
177.84.73(8)
99.85(16)
124.0(4)
37.4(8)
3.3. Preparation of the gold selenoureato complexes
To a solution of HLSe in MeOH was added NaOMe (1.1 equiv).
After 15 min of stirring, the phosphine gold chloro complex was
30.6(7)
32(2)
24(1)

A. Molter et al. / Tetrahedron 68 (2012) 10586e10591
10589
added to the mixture, which was subsequently left to stir at room
temperature over night protected from light. Two workup methods
were then used:
(%) for C18H29N3AuO3PSe (642.34 g/mol): C 33.66, H 4.55, N 6.54;
found: C 34.08, H 4.88, N 6.61.
3.3.4. [Au2(LSe)2(
with diethyl ether: yellow solid. Yield: 0.137 g (81%). 1H NMR
(400 MHz, CDCl3):
m-dppm)] (4). Workup method B, precipitated
(A) When the product precipitated out of the reaction mixture, the
solid was isolated by filtration, washed with small amounts of
methanol, water and diethyl ether and subsequently dried in
air.
(B) When a solution formed, this was evaporated to dryness and
the residue was dissolved in dichloromethane and passed
through Celite. The solution was concentrated and the product
precipitated upon addition of a suitable solvent such as diethyl
ether, hexane or pentane. The solids were isolated by filtration
and subsequently dried in air.
d
¼1.30 (br s, 12H, NCH2CH3), 3.07 (ABX-t, 2H,
PCH2), 3.66 (br s, 4H, NCH2CH3), 3.92 (br s, 4H, NCH2CH3), 7.19 (m,
8H, m-PPh2), 7.29e7.41 (m, 12H, o-PPh2, p-PPh2), 7.66 (d, J¼7.4 Hz,
4H, H-2), 7.84 (d, J¼8.2 Hz, 4H, H-3) ppm. 31P{1H} NMR (162 MHz,
CDCl3):
d
¼30.1 ppm. 13C{1H} NMR (101 MHz, CDCl3):
¼13.2 (br s,
d
NCH2CH3), 29.5 (ABX-t, PCH2), 46.0 (br s, NCH2CH3), 48.3 (br s,
NCH2CH3), 122.4 (C-2), 128.2 (m, i-PPh2), 129.0 (ABX-t, m-PPh2),
129.9 (C-3), 131.8 (p-PPh2), 133.2 (ABX-t, o-PPh2), 143.8 (C-1), 148.4
(C-4), 163.2 (C]O), 166.7 (CeSe) ppm. 77Se NMR (76 MHz, CDCl3):
277 ppm. IR (KBr disk) n: 1342 (s, NO2), 1518 (s, NO2), 1569 (s, C]O),
2931 (w, Csp3 eH), 2973 (w, Csp3 eH), 3052 (w, Csp2 eH) cmꢀ1. Ele-
mental analysis, calcd (%) for C49H50N6Au2O6P2Se2 (1432.76 g/mol):
C 41.08, H 3.52, N 5.87; found: C 40.91, H 3.15, N 6.03.
3.3.1. [Au(LSe)(PPh3)] (1). Workup method B, precipitated with
diethyl ether: yellow solid. Yield: 0.124 g (78%). 1H NMR (400 MHz,
CDCl3):
d
¼1.30 (br s, 6H, NCH2CH3), 3.77 (br s, 4H, NCH2CH3),
7.31e7.36 (m, 12H, o-PPh3, m-PPh3), 7.45 (m, 3H, p-PPh3), 7.74 (d,
3.3.5. [Au2(LSe)2(
methanol: yellow solid. Yield: 0.167 g (100%). 1H NMR (400 MHz,
CDCl3):
m-dppe)] (5). Workup method B, precipitated with
J¼7.7 Hz, 2H, H-3), 7.93 (d, J¼8.6 Hz, 2H, H-2) ppm. 31P{1H} NMR
(162 MHz, CDCl3):
d
¼38.1 ppm. 13C{1H} NMR (101 MHz, CDCl3):
d
¼1.31 (br s, 12H, NCH2CH3), 2.66 (s, 4H, PCH2), 3.79 (br s,
d
¼13.4 (NCH2CH3), 45.8 (NCH2CH3), 47.9 (NCH2CH3), 122.5 (C-3),
8H, NCH2CH3), 7.35 (t, J¼7.3 Hz, 8H, m-PPh2), 7.44 (t, J¼7.3 Hz, 4H,
p-PPh2), 7.55 (t, J¼6.1 Hz, 8H, o-PPh2), 7.79 (d, J¼8.4 Hz, 4H, H-2),
7.88 (d, J¼8.5 Hz, 4H, H-3) ppm. 31P{1H} NMR (162 MHz, CDCl3):
3
1
129.0 (d, JPeC¼11.5 Hz, m-PPh3), 129.3 (d, JPeC¼56.4 Hz, i-PPh3),
130.0 (C-2), 131.5 (d, 4JPeC¼2.4 Hz, p-PPh3), 134.0 (d, 2JPeC¼13.9 Hz,
o-PPh3), 144.1 (C-1), 148.5 (C-4), 166.2 (C]O), 168.6 (CeSe) ppm.
d
¼37.3 ppm. 13C{1H} NMR (101 MHz, CDCl3):
¼13.4 (NCH2CH3),
d
77Se NMR (76 MHz, CDCl3): 236 ppm. IR (KBr disk)
n
: 1343 (s, NO2),
1519 (s, NO2), 1579 (m, C]O), 2931 (w, Csp3 eH), 2974 (w, Csp3 eH),
3053 (w, Csp2 eH) cmꢀ1
Elemental analysis, calcd (%) for
23.7 (ABX-t, PCH2), 47.9 (NCH2CH3), 122.7 (C-2), 128.7 (m, i-PPh2),
129.2 (ABX-t, m-PPh2), 129.9 (C-3), 131.9 (p-PPh2), 133.3 (ABX-t, o-
PPh2), 144.0 (C-1), 148.7 (C-4), 164.3 (C]O), 168.7 (CeSe) ppm. 77Se
.
C30H29N3AuO3PSe (786.47 g/mol): C 45.81, H 3.72, N 5.34; found: C
46.45, H 3.74, N 5.04.
NMR (76 MHz, CDCl3): 231 ppm. IR (KBr disk)
(s, NO2), 1582 (s, C]O), 2932 (m, Csp3 eH), 2964 (m, Csp3 eH), 3058
(w, Elemental analysis, calcd (%) for
Csp2 eH) cmꢀ1
n: 1342 (s, NO2), 1518
.
C50H52N6Au2O6P2Se2 (1446.79 g/mol): C 41.51, H 3.62, N 5.81;
found: C 41.29, H 3.46, N 5.68.
3.3.2. Au(LSe)P(o-tolyl)3] (2). Workup method B, precipitated with
diethyl ether: colourless solid. Yield: 0.129 g (77%). 1H NMR
(400 MHz, CDCl3):
d
¼1.27 (br s, 6H, NCH2CH3), 2.45 (s, 9H, CH3
3.3.6. [Au2(LSe)2(
hexane: yellow solid. Yield: 0.130 g (78%). 1H NMR (400 MHz,
CDCl3):
m-dppp)] (6). Workup method B, precipitated with
P(o-tolyl)3), 3.70 (br s, 2H, NCH2CH3), 3.81 (br s, 2H, NCH2CH3),
6.90 (m, 3H, H-60 P(o-tolyl)3), 7.12 (t, J¼7.5 Hz, 3H, H-50 P(o-
tolyl)3), 7.25 (t, J¼7.0 Hz, 3H, H-30 P(o-tolyl)3), 7.41 (t, J¼7.5 Hz,
3H, H-40 P(o-tolyl)3), 7.78 (d, J¼8.7 Hz, 2H, H-2), 7.88 (d, J¼8.7 Hz,
d
¼1.31 (br s, 12H, NCH2CH3), 1.71 (m, 2H, CH2), 2.57 (s, 4H,
PCH2), 3.77 (br s, 8H, NCH2CH3), 7.34 (dt, J¼7.5, 1.7 Hz, 8H, m-PPh2),
7.34 (m, 4H, p-PPh2), 7.50 (m, 8H, o-PPh2), 7.82 (br s, 4H, H-2), 7.88
2H, H-3) ppm. 31P{1H} NMR (162 MHz, CDCl3):
d
¼19.7 ppm. 13C
(br s, 4H, H-3) ppm. 31P{1H} NMR (162 MHz, CDCl3):
d
¼31.6 ppm.
{1H} NMR (101 MHz, CDCl3):
d
¼13.3 (NCH2CH3), 23.0 (d,
13C{1H} NMR (101 MHz, CDCl3):
d
¼13.3 (NCH2CH3), 19.5 (m, CH2),
3JPeC¼11.1 Hz, CH3 P(o-tolyl)3), 45.5 (NCH2CH3), 47.8 (NCH2CH3),
28.3 (dd, 1JPeC¼33.6 Hz, 3JPeC¼11.5 Hz, PCH2), 46.0 (br s, NCH2CH3),
1
122.4 (C-2), 125.6 (d, JPeC¼54.9 Hz, C-10 P(o-tolyl)3), 126.5 (d,
3
48.2 (br s, NCH2CH3), 122.7 (C-2), 129.1 (d, JPeC¼11.3 Hz, m-PPh2),
3JPeC¼9.8 Hz, C-50 P(o-tolyl)3), 129.6 (C-3), 131.5 (d, JPeC¼1.6 Hz,
4
129.2 (d, 1JPeC¼54.2 Hz, i-PPh2), 130.0 (C-3), 131.6 (d, 4JPeC¼2.3 Hz,
3
C-40 P(o-tolyl)3), 132.1 (d, JPeC¼8.7 Hz, C-30 P(o-tolyl)3), 133.4 (d,
2
p-PPh2), 133.2 (d, JPeC¼13.4 Hz, o-PPh2), 143.8 (C-1), 148.7 (C-4),
2JPeC¼9.3 Hz, C-60 P(o-tolyl)3), 142.9 (d, JPeC¼12.5 Hz, C-20 P(o-
2
166.0 (C]O), 167.9 (CeSe) ppm. 77Se NMR (76 MHz, CDCl3):
tolyl)3), 144.3 (C-1), 148.4 (C-4), 167.5 (C]O), 167.8 (CeSe) ppm.
242 ppm. IR (KBr disk) n: 1342 (s, NO2), 1519 (s, NO2), 1569 (s, C]O),
77Se NMR (76 MHz, CDCl3): 219 ppm. IR (KBr disk)
n: 1342 (s,
2930 (w, Csp3 eH), 2972 (w, Csp3 eH), 3052 (w, Csp2 eH) cmꢀ1. Ele-
mental analysis, calcd (%) for C51H54N6Au2O6P2Se2 (1460.81 g/mol):
C 41.93, H 3.73, N 5.75; found: C 41.69, H 3.77, N 5.88.
NO2), 1519 (s, NO2), 1579 (m, C]O), 2931 (w, Csp3 eH), 2972 (w,
Csp3 eH), 3058 (w, Csp2 eH) cmꢀ1. Elemental analysis, calcd (%) for
C33H35N3AuO3PSe (828.55 g/mol): C 47.84, H 4.26, N 5.07; found:
C 47.38, H 3.93, N 4.84.
3.3.7. [Au2(LSe)2(
Yield: 0.118 g (34%). 1H NMR (400 MHz, CDCl3):
m-dppb)] (7). Workup method A: yellow solid.
d
¼1.31 (br s, 12H,
3.3.3. [Au(LSe)(PEt3)] (3). Workup method B, yellow viscous solid.
NCH2CH3), 1.60 (m, 2H, CH2), 2.18 (s, 4H, PCH2), 3.68 (br s, 4H,
NCH2CH3), 3.90 (br s, 4H, NCH2CH3), 7.34e7.44 (m, 8H, m-PPh2),
7.41e7.48 (m, 12H, p-PPh2, o-PPh2), 7.89 (d, J¼7.8 Hz, 4H, H-2), 7.97
(d, J¼8.5 Hz, 4H, H-3) ppm. 31P{1H} NMR (162 MHz, CDCl3):
Yield: 0.267 g (97%). 1H NMR (400 MHz, CDCl3):
d¼0.84 (dt,
3JHeP¼18.5 Hz, J¼7.6 Hz, 9H, PCH2CH3), 1.10 (br s, 6H, NCH2CH3), 1.43
(dq, 2JHeP¼9.8 Hz, J¼7.7 Hz, 6H, PCH2), 3.51 (br s, 2H, NCH2CH3), 3.64
(br s, 2H, NCH2CH3), 8.01 (d, J¼9.0 Hz, 2H, H-3), 8.06 (d, J¼9.0 Hz, 2H,
d
¼34.6 ppm. 13C{1H} NMR (101 MHz, CDCl3):
¼13.1 (NCH2CH3),
d
H-2) ppm. 31P{1H} NMR (162 MHz, CDCl3):
d
¼35.9 ppm. 13C{1H} NMR
2
3
26.5 (dd, JPeC¼18.0 Hz, JPeC¼4.3 Hz, PCH2CH2), 27.8 (d,
1JPeC¼34.1 Hz, PCH2), 46.2 (br s, NCH2CH3), 48.7 (br s, NCH2CH3),
(101 MHz, CDCl3):
d
¼8.2 (PCH2CH3), 12.7 (NCH2CH3), 12.9 (NCH2CH3),
1
3
17.2 (d, JPeC¼32.7 Hz, PCH2CH3), 45.0 (br s, NCH2CH3), 47.6 (br s,
NCH2CH3), 122.3 (C-3), 129.8 (C-2), 144.1 (C-1), 148.3 (C-4), 166.6 (C]
O), 167.1 (CeSe) ppm. 77Se NMR (76 MHz, CDCl3): 242 ppm. IR (KBr
122.8 (C-2), 129.0 (d, JPeC¼11.5 Hz, m-PPh2), 129.3 (i-PPh2), 129.9
2
(C-3), 131.5 (p-PPh2), 133.5 (d, JPeC¼13.5 Hz, o-PPh2), 142.9 (C-1),
148.9 (C-4), 164.3 (C]O), 166.7 (CeSe) ppm. 77Se NMR (114 MHz,
disk)
n: 1342 (s, NO2), 1519 (s, NO2), 1576 (m, C]O), 2932 (m, Csp3 eH),
CDCl3): 240 ppm. IR (KBr disk)
n: 1343 (s, NO2), 1519 (s, NO2), 1583
2967 (m, Csp3 eH), 3068 (w, Csp2 eH) cmꢀ1. Elemental analysis, calcd
(s, C]O), 2930 (m, Csp3 eH), 2974 (m, Csp3 eH), 3054 (w, Csp2 eH)

10590
A. Molter et al. / Tetrahedron 68 (2012) 10586e10591
cmꢀ1
(1474.84 g/mol):
H 3.81, N 5.38.
.
Elemental analysis, calcd (%) for C52H56N6Au2O6P2Se2
FR591) producing Mo K
a-radiation (l¼0.71073 A) equipped with
ꢀ
C
42.35,
H
3.83,
N
5.70; found:
C
41.27,
a graphite monochromator. Data collection and integration were
controlled by the collect package.52 Scaling and absorption correc-
tion were performed using SADABS.53 The structures were solved
using Direct Methods or Patterson Methods and refined by Full-
Matrix-Least-Squares against F2. The non-hydrogen atoms were
refined anisotropicallyand hydrogen atoms were placed at idealised
positions and refined using the riding model. All calculations were
carried out using the program Olex2.54 Important crystallographic
and refinement parameters are collected inTable 2. The data set for 1
contained residual electron density due to severely disordered sol-
vent molecules. After many unsuccessful attempts at modelling this
disorder, the SQUEEZE algorithm within PLATON was applied.55
3.3.8. [Au2(LSe)2(
m-dppf)] (8). Workup method A: yellow solid.
Yield: 0.158 g (100%). 1H NMR (400 MHz, CDCl3):
d
¼1.30 (br s, 12H,
NCH2CH3), 3.76 (br s, 8H, NCH2CH3), 4.21 (s, 4H, H-20, PC5H4), 4.60
(s, 4H, H-30, PC5H4), 7.29e7.35 (m, 16H, o-PPh2, m-PPh2), 7.40e7.43
(m, 4H, p-PPh2), 7.80 (d, J¼8.6 Hz, 4H, H-2), 7.94 (d, J¼8.6 Hz, 4H, H-
3) ppm. 31P{1H} NMR (162 MHz, CDCl3):
d
¼32.8 ppm. 13C{1H} NMR
(101 MHz, CDCl3):
d
¼13.5 (NCH2CH3), 45.8 (NCH2CH3), 47.8
1
(NCH2CH3), 72.1 (d, JPeC¼65.0 Hz, C-10, PC5H4), 74.7 (d,
3JPeC¼8.1 Hz, C-30, PC5H4), 74.8 (d, JPeC¼12.9 Hz, C-20, PC5H4),
2
3
122.6 (C-2), 128.7 (d, JPeC¼11.6 Hz, m-PPh2), 130.0 (C-3), 130.6 (d,
1JPeC¼57.5 Hz, i-PPh2), 131.3 (d, JPeC¼2.2 Hz, p-PPh2), 133.4 (d,
4
Acknowledgements
2JPeC¼14.1 Hz, o-PPh2), 144.1 (C-1), 148.6 (C-4), 165.8 (C]O), 168.4
(CeSe) ppm. 77Se NMR (114 MHz, CDCl3): 235 ppm. IR (KBr disk)
n:
A.M. thanks the University of Wuppertal for a scholarship. We
gratefully acknowledge a generous donation of selenium metal
from Retorte GmbH.
1342 (s, NO2), 1519 (s, NO2), 1574 (m, C]O), 2930 (w, Csp3 eH), 2974
(w, Csp3 eH), 3052 (w, Csp2 eH) cmꢀ1. Elemental analysis, calcd (%)
for C58H56N6Au2FeO6P2Se2 (1602.75 g/mol): C 43.46, H 3.52, N 5.24;
found: C 43.31, H 3.45, N 5.24.
References and notes
1. Douglass, I. B. J. Am. Chem. Soc. 1937, 59, 740e742.
3.4. X-ray crystallography
2. Molter, A.; Rust, J.; Lehmann, C. W.; Mohr, F. Arkivoc 2011, vi, 10e17.
3. Wei, T. B.; Wang, H.; Lin, Q.; Zhang, Y. M. Chin. J. Org. Chem. 2005, 28, 1565e1569.
4. Wei, T. B.; Wang, H.; Lin, Q.; Zhang, Y. M. Chem. J. Chin. Univ. 2006, 27,1680e1682.
5. Koketsu, M.; Yamamura, Y.; Aoki, H.; Ishihara, H. Phosphorus, Sulfur Silicon Relat.
Elem. 2006, 181, 2699e2708.
Crystals suitable for X-ray diffraction were grown by slow diffu-
sion of diethyl ether into a saturated dichloromethane solution of
the complex 1, 5 or 8, respectively. Diffraction data for compounds 1
and 5 were collected using an Oxford Diffraction Gemini E Ultra
diffractometer, equipped with an EOS CCD area detector and a four-
circle kappa goniometer. For the data collection the Mo source
emitting graphite-monochromated Mo K
was used. Data integration, scaling and empirical absorption cor-
rection was carried out using the CrysAlis Pro program package.51
Diffraction data for compound 8 were collected at 100 K using
a Nonius KappaCCD diffractometer with a rotating anode (Nonius
6. Zhou, Y.; Heimgartner, H. Helv. Chim. Acta 2000, 83, 539e553.
€
7. Kohler, R.; Beyer, L.; Moll, M. Tetrahedron 1990, 46, 7735e7738.
8. Weber, G.; Hartung, J.; Beyer, L. Tetrahedron Lett. 1988, 29, 3475e3476.
9. Liebscher, J.; Hartmann, H. Z. Chem. 1976, 16, 18e19.
10. Beyer, L.; Kirmse, R.; Hoyer, E. Z. Chem. 1975, 15, 197.
ꢀ
a
radiation (
l
¼0.71073 A)
11. Shome, S. C.; Mazumdar, M.; Das, S. K. J. Indian Chem. Soc. 1980, 57, 69e72.
€
12. Schuster, M.; Konig, K. H. Fresenius Z. Anal. Chem. 1987, 327, 102e104.
€
13. Schuster, M.; Konig, K. H. Fresenius Z. Anal. Chem. 1988, 331, 383e386.
14. Bruce, J. C.; Revaprasadu, N.; Koch, K. R. New J. Chem. 2007, 31, 1647e1653.
15. Akhtar, J.; Mehmood, R. F.; Malik, M. A.; Iqbal, N.; O’Brien, P.; Raftery, J. Chem.
Commun. 2011, 1899e1901.
16. Akhtar, J.; Malik, M. A.; Stubbs, S. K.; O’Brien, P.; Helliwell, M.; Binks, D. J. Eur. J.
Inorg. Chem. 2011, 2984e2990.
17. Akhtar, J.; Akhtar, M.; Malik, M. A.; O’Brien, P.; Raftery, J. J. Am. Chem. Soc. 2012,
134, 2485e2487.
Table 2
Crystallographic and refinement details for complexes 1, 5 and 8
18. Bensch, W.; Schuster, M. Z. Anorg. Allg. Chem. 1993, 619, 1689e1692.
19. Schuster, M.; Bensch, W. Z. Anorg. Allg. Chem. 1994, 620, 737e742.
20. Kampf, M.; Richter, R.; Hennig, L.; Eidner, A.; Baldamus, J.; Kirmse, R. Z. Anorg.
Allg. Chem. 2004, 630, 2677e2686.
21. Kampf, M.; Richter, R.; Gerber, S.; Kirmse, R. Z. Anorg. Allg. Chem. 2004, 630,
1437e1443.
22. Bensch, W.; Schuster, M. Z. Anorg. Allg. Chem. 1993, 619, 791e795.
23. Bensch, W.; Schuster, M. Z. Anorg. Allg. Chem. 1993, 619, 786e790.
24. Bensch, W.; Schuster, M. Z. Anorg. Allg. Chem. 1994, 620, 177e182.
25. Bensch, W.; Schuster, M. Z. Anorg. Allg. Chem. 1994, 620, 1479e1482.
26. Schuster, M.; Bensch, W. Z. Naturforsch. 1994, 49b, 1615e1619.
27. Kampf, M.; Richter, R.; Griebel, J.; Weller, A.; Kirmse, R. Z. Anorg. Allg. Chem.
2005, 631, 698e708.
28. Bruce, J. C.; Koch, K. R. Acta Crystallogr. 2008, C64, m1em4.
29. Kirmse, R.; Beyer, L.; Hoyer, E. Chem. Phys. Lett. 1977, 49, 544e546.
30. Bredenkamp, A.; Zeng, X.; Mohr, F. Polyhedron 2012, 33, 107e113.
31. Molter, A.; Mohr, F. Coord. Chem. Rev. 2010, 254, 19e45.
32. Vergara, E.; Miranda, S.; Mohr, F.; Cerrada, E.; Tiekink, E. R. T.; Romero, P.; La-
guna, M. Eur. J. Inorg. Chem. 2007, 2926e2933.
[Au(LSe
(PPh3)] (1)
30H29
AuN3O3PSe
786.46
)
[Au2(LSe
)
[Au2(LSe
)
2
(m-dppf)] (8)
2
(
m-dppe)] (5)
Empirical formula
C
C
50H52Au2
C58H56N6Au2
FeO6P2Se2
1602.73
N6O6P2Se2
1446.77
Molecular
weight (g molꢀ1
Crystal colour
and shape
)
Yellow block
Yellow block
Yellow block
Crystal system
Space group
Monoclinic
C2/c
27.3351(6)
8.56693(19)
26.8640(5)
Triclinic
P-1
Monoclinic
C2/c
26.229(4)
8.4240(14)
26.765(4)
ꢀ
a (A)
8.6513(19)
10.8626(11)
15.3145(13)
74.369(8)
88.486(11)
66.708(15)
1267.8(3)
130
ꢀ
b (A)
ꢀ
c (A)
a
b
g
(ꢁ)
(ꢁ)
(ꢁ)
94.6948(19)
94.579(3)
3
ꢀ
V (A )
6269.9(2)
150
8
5894.8(17)
100
4
33. Dolfen, D.; Schottler, K.; Seied-Mojtaba, V.; Jakupec, M. A.; Keppler, B. K.; Tie-
kink, E. R. T.; Mohr, F. J. Inorg. Biochem. 2008, 102, 2067e2071.
34. Gallenkamp, D.; Tiekink, E. R. T.; Mohr, F. Phosphorus, Sulfur Silicon 2008, 183,
1050e1056.
T (K)
Z
Calcd density
1
1.666
1.895
1.806
(g cmꢀ3
)
35. Miranda, S.; Vergara, E.; Mohr, F.; de Vos, D.; Cerrada, E.; Mendía, A.; Laguna, M.
Crystal size (mm3)
m
0.1ꢂ0.05ꢂ0.03 0.38ꢂ0.22ꢂ0.06 0.08ꢂ0.06ꢂ0.02
Inorg. Chem. 2008, 47, 5641e5648.
(mmꢀ1
range (ꢁ)
)
5.938
5.90e58.66
18,782
7.333
7.04e58.80
10,888
6.551
3.06e59.50
73,964
€
36. Alagoz, C.; Brauer, D. J.; Mohr, F. J. Organomet. Chem. 2009, 694, 1283e1288.
2
Q
37. Fuge, F.; Lehmann, C.; Mohr, F. J. Organomet. Chem. 2009, 694, 2395e2401.
38. Gallenkamp, D.; Porsch, T.; Molter, A.; Tiekink, E. R. T.; Mohr, F. J. Organomet.
Chem. 2009, 694, 2380e2385.
No. of data collected
No. of unique data
7345[R
5818[R
8378[R
39. Gold Chemistry. Applications and Future Directions in the Life Sciences; Mohr, F.,
Ed.; Wiley-VCH: Weinheim, 2009.
40. Schuh, E.; Valiahdi, S. M.; Jakupec, M. A.; Keppler, B. K.; Chiba, P.; Mohr, F.
Dalton Trans. 2009, 10841e10845.
(int)¼0.0276]
(int)¼0.0737]
(int)¼0.1078]
Ra1 [F2>2
wRb2 (all data)
c (all data)
s
(F2)]
0.0334
0.0602
0.0368
0.0708
1.058
0.1502
1.039
3.8/ꢀ5.2
0.1102
1.030
1.6/ꢀ2.2
S
41. Ben Dahman Andaloussi, M.; Mohr, F. J. Organomet. Chem. 2010, 695, 1276e1280.
Largest diff. peak/hole 1.4/ꢀ1.3
€
42. Bippus, P.;Molter, A.; Muller, D.; Mohr, F. J. Organomet. Chem. 2010, 695,1657e1662.
ꢀꢀ3
(e A ) min/max
43. Pisiewicz, S.; Rust, J.; Lehmann, C. W.; Mohr, F. Polyhedron 2010, 29, 1968e1972.

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10591
44. Bippus, P.; Skocic, M.; Jakupec, M. A.; Keppler, B. K.; Mohr, F. J. Inorg. Biochem.
49. Bensch, W.; Schuster, M. Z. Anorg. Allg. Chem. 1992, 611, 99e102.
50. Uson, R.; Laguna, A.; Laguna, M. Inorg. Synth. 1989, 26, 85e91.
ꢁ
2011, 105, 462e466.
45. Molter, A.; Mohr, F. Dalton Trans. 2011, 40, 3754e3758.
46. Molter, A.; Rust, J.; Lehmann, C. W.; Deepa, G.; Chiba, P.; Mohr, F. Dalton Trans.
2011, 40, 9810e9820.
51. CrysAlis Pro 171.33.49; Oxford Diffraction: Oxford, UK, 2009.
52. COLLECT, data Collection Software; Nonius BV: Delft, NL, 1999.
53. SMART Version 6.24; Bruker AXS: Madison, WI, 1997.
47. Molter, A.; Bill, E.; Mohr, F. Inorg. Chem. Commun. 2012, 17, 124e127.
48. Schuh, E.; Pfluger, C.; Citta, A.; Folda, A.; Rigobello, M. P.; Bindoli, A.; Casini, A.;
54. Dolomanov, O. V.; Bourhis, L. J.; Gildea, R. J.; Howard, J. A. K.; Puschmann, H. J.
Appl. Crystallogr. 2009, 42, 339e341.
€
Mohr, F. J. Med. Chem. 2012, 55, 5518e5528.
55. Spek, A. L. Acta Cystallogr. 1990, A46, C34.