New organomercury(II) compounds containing intramolecular N→Hg interactions: Crystal and molecular structure of [2-(Me2 NCH2)C6H4]HgCl and [2-(Me2NCH2)C6H4] Hg[S(S)PPh2]

Article abstract of DOI:10.1016/j.jorganchem.2003.10.044

[2-(Me₂NCH₂)C₆H₄]HgCl (1) was prepared by reacting HgCl₂ with [2-(Me₂ NCH₂)C₆H₄]Li in diethyl ether. The reactions of 1 with the sodium or ammonium salt of the appropriate thiophosphinato ligand, in 1:1 molar ratio, afford the isolation of [2-(Me₂NCH₂)C₆H₄]Hg[S(S) PR₂] [R=Me (2), Et (3), Ph (4)], [2-(Me₂ NCH₂)C₆H₄]Hg[S(O)PPh₂] (5) and [2-(Me₂NCH₂)C₆H₄] Hg[S(S)P(OⁱPr)₂] (6). The compounds were investigated by IR and multinuclear NMR (¹H, ¹³C and ³¹P) spectroscopy. The molecular structures of 1 and 4 were determined by single-crystal X-ray diffraction. Due to the strong intramolecular coordination of the N atom of the pendant CH₂NMe₂ arm [Hg((1)-N(1) 2.764(6) and 2.725(4) ? in 1 and 4, respectively] both compounds exhibit a T-shaped (C,N)HgX core in the molecular unit, with almost linear arrangement of the covalent bonds [C(1)-Hg(1)-Cl(1) 176.93(18)° in 1, and C(1)-Hg(1)-S(1) 169.54(16)° in 4]. The crystals of 1 contain discrete monomeric molecules, while the crystals of 4 contain dimer associations built through asymmetric bridging dithiophosphinato ligands [Hg(1)-S(1) 2.3911(16) ?, Hg(1)·S(2a) 3.102(2) ?], thus resulting in an overall pseudo-trigonal bipyramidal (or seesaw) (C, N)HgS₂ core, with the nitrogen atom and the weekly bonded sulfur atom in equatorial positions [N(1)-Hg(1)·S(2a) 82.01(10)°].

Full text of DOI:10.1016/j.jorganchem.2003.10.044

Journal of Organometallic Chemistry 689 (2004) 1172–1179
www.elsevier.com/locate/jorganchem
New organomercury(II) compounds containing
intramolecular N ! Hg interactions: crystal and molecular
structure of [2-(Me2NCH2)C6H4]HgCl and
[2-(Me2NCH2)C6H4]Hg[S(S)PPh2]
a
Oana Bumbu , Cristian Silvestru , M. Concepcion Gimeno , Antonio Laguna
a,
b
b
*
ꢀ
a
Facultatea de Chimie si Inginerie Chimica, Universitatea Babes-Bolyai, RO-3400 Cluj-Napoca, Romania
Departamento de Quꢀımica Inorgꢀanica, Instituto de Ciencia de Materiales de Aragꢀon, Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain
b
Received 9 September 2003; accepted 30 October 2003
Abstract
[2-(Me2NCH2)C6H4]HgCl (1) was prepared by reacting HgCl2 with [2-(Me2NCH2)C6H4]Li in diethyl ether. The reactions of
1 with the sodium or ammonium salt of the appropriate thiophosphinato ligand, in 1:1 molar ratio, afford the isolation of
[2-(Me2NCH2)C6H4]Hg[S(S)PR2] [R ¼ Me (2), Et (3), Ph (4)], [2-(Me2NCH2)C6H4]Hg[S(O)PPh2] (5) and [2-(Me2NCH2)C6H4]Hg-
[S(S)P(OiPr)2] (6). The compounds were investigated by IR and multinuclear NMR (1H, 13C and 31P) spectroscopy. The molecular
structures of 1 and 4 were determined by single-crystal X-ray diffraction. Due to the strong intramolecular coordination of the
ꢁ
N atom of the pendant CH2NMe2 arm [Hg(1)–N(1) 2.764(6) and 2.725(4) A in 1 and 4, respectively] both compounds exhibit a
T-shaped (C,N)HgX core in the molecular unit, with almost linear arrangement of the covalent bonds [C(1)–Hg(1)–Cl(1) 176.93(18)ꢀ
in 1, and C(1)–Hg(1)–S(1) 169.54(16)ꢀ in 4]. The crystals of 1 contain discrete monomeric molecules, while the crystals of 4 contain
ꢁ
dimer associations built through asymmetric bridging dithiophosphinato ligands [Hg(1)–S(1) 2.3911(16) A, Hg(1)ꢀ ꢀ ꢀS(2a) 3.102(2)
ꢁ
A], thus resulting in an overall pseudo-trigonal bipyramidal (or seesaw) (C,N)HgS2 core, with the nitrogen atom and the weekly
bonded sulfur atom in equatorial positions [N(1)–Hg(1)ꢀ ꢀ ꢀS(2a) 82.01(10)ꢀ].
ꢁ 2004 Elsevier B.V. All rights reserved.
1. Introduction
few mercury(II) compounds containing phenyl groups
with pendent arms was reported so far, i.e. [2-
(R2NCH2)C6H4]2Hg (R ¼ Me [7,8], Et [9]), [2-
(Me2NCH2)C6H4]HgCl [7], [2-{Me2NC(Me)H}C6H4]
HgX (X ¼ Cl, Br, I) [10], and [2-{Me2NC(Me)H}C10H6]
HgX (X ¼ Cl, Br, I) [11]. In the case of the above
chlorides the solid state structure determinations re-
vealed, in addition of internal N ! Hg coordination, the
association of the molecular units through weak Hg–
Organomercury(II) compounds of the type R2Hg and
RHgX (R ¼ alkyl or aryl; X ¼ halide) [1] have received a
lot of attention for the last three decades mainly related
to the search for biologically active compounds and
versatile reagents in controlled transmetallation reac-
tions [2]. The influence of secondary interactions be-
tween mercury and donor atoms as nitrogen on the
structures of organomercury compounds was reviewed
by KuzÕmina and Struchkov [3]. Cyclometallated orga-
nomercury(II) chlorides containing N-donor functiona-
lised aryl ligands were investigated in the context of their
use as transmetallation reagents [4–6]. The synthesis of
Clꢀ ꢀ ꢀHg intermolecular bridges weak (often at the limit
P
of the sum of the van der Waals radii, vdW(Hg,Cl) 3.4
ꢁ
ꢁ
A [12]) into dimers [Fig. 1(a), Hgꢀ ꢀ ꢀCl 3.239(10) A] [4],
tetramers [Fig. 1(b), Hgꢀ ꢀ ꢀCl 3.184(5), 3.410(6), 3.442(6)
ꢁ
ꢁ
A] [5,6], single-bridged [Fig. 1(c), Hgꢀ ꢀ ꢀCl 3.303(3) A]
[10] or doubly bridged polymers [Fig. 1(c), Hgꢀ ꢀ ꢀCl
ꢁ
3.271(5), 3.330(5) A] [11]. The Hg atom in these com-
* Corresponding author. Tel.: +40-264-193833; fax: +40-264-190818.
E-mail address: cristi@chem.ubbcluj.ro (C. Silvestru).
pounds was suggested to be a stereocenter in solid state
since the (C,N)HgX core is slightly pyramidal [10,11].
0022-328X/$ - see front matter ꢁ 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2003.10.044

O. Bumbu et al. / Journal of Organometallic Chemistry 689 (2004) 1172–1179
1173
N2
N1
Cl2
Cl1
Hg1
Hg2
C1
N2
Hg1
C1
N1
Hg1
C1
C12
Cl1
Cl1
N1
Cl1
C12
N1
N2
N2
Hg2
Hg1
C1
Cl2
(a)
(b)
C1
C1
N1
C1
N1
Cl1
Cl1
Hg1
Hg1
N1
Hg1
Cl1
Cl1
Hg1
Hg1
N1
Cl1
N1
Hg1
Cl1
C1
C1
N1
C1
(d)
(c)
S1
N1
Hg1
P1
C11
S2
(e)
Fig. 1. Associations in the crystal of (a) [2-(9-Ph-1,10-phenanthrolinyl-2)phenyl]HgCl [4]; (b) [2-(2-pyridyl)phenyl]HgCl [5,6]; (c) [2-{Me2NC-
(Me)H}C6H4]HgCl [10]; (d) [2-{Me2NC(Me)H}C10H6]HgCl [11]; and (e) [2-(2-pyridyl)phenyl]Hg[S(S)PCy2] [19].
Variable temperature NMR studies in solution have
revealed that the above chiral organomercury halides
exhibit a temperature-dependent equilibrium between
two- and three-coordinate species. The use of [2-
{Me2NC(Me)H}C6H4]HgCl as a transmetallation re-
agent in the synthesis of chiral Ru(II) complexes was
reported [13,14].
However, no derivatives with anionic ligands con-
taining a second potential coordinating atom, to com-
pete the nitrogen atom of the C(R)HNMe2 pending arm
for coordination to the metal centre have been prepared
so far. On the other hand, thiophosphorus ligands of the
type [R2P(X)S]ꢁ (R ¼ alkyl, aryl, alkoxy; X ¼ O, S) are
well known to involve usually both chalcogen atoms in
coordination to the metal atom in organomercury(II)
derivatives thus resulting in dimeric [MeHg{S(S)PPh2}]2
[15] and [PhHg{S(S)P(OEt)2}]2 [16] species [structure I –
S,S-bimetallic biconnective phosphorus ligands] or
polymeric [PhHg{S(S)PEt2}]n [structure II – S,S0,S0-bi-
metallic triconnective ligands] [17] and [MeHg{S(O)
PPh2}]n [structure III – S,O,O-trimetallic triconnective
ligands] associations [18]. Only one example of an
[organo-C,N]mercury(II) dithiophosphinate containing
intramolecular N ! Hg coordination was reported, i.e.

1174
O. Bumbu et al. / Journal of Organometallic Chemistry 689 (2004) 1172–1179
the monomeric [2-(2-pyridyl)phenyl-(C,N)]Hg[S(S)PCy2]
[Fig. 1(e)], in this case the dithio ligand acting as a
monometallic monoconnective (monodentate) unit [19].
2.2. IR spectra
The infrared spectra of 4 and 5 exhibit, in addition to
the expected strong absorptions due to the organic
groups bonded to mercury, strong bands in the 650–540
cmꢁ1 region and around 1165 cmꢁ1 for 5, which were
assigned to phosphorus–sulfur and phosphorus–oxygen
stretching vibrations. The presence of absorption bands
corresponding to P–S single bond (575 cmꢁ1) and P@O
double bond (1165 cmꢁ1) in the infrared spectrum of 5
indicates a primary coordination of the phosphorus li-
gand to the metal centre through the sulfur atom (cf. the
methyl esters: 1027 (P–O), 635 (P@S) cmꢁ1 for
Ph2P(S)OMe [20]; 1200 (P@O), 568 (P–S) cmꢁ1 for
Ph2P(O)SMe [20]; for a detailed discussion, see [21]).
For both compounds the infrared data are consistent
with a basically S-monometallic monoconnective coor-
dination pattern of the phosphorus ligand in solid state.
This behavior of a monothiophosphinato moiety con-
trasts with its ability to exhibit a bridging pattern as
found in the polymeric [MeHg{S(O)PPh2}]n [18]. The
primary S-coordination of the monothiophosphinato
moiety in the solid state is consistent with the magnitude
of the 31P chemical shift found for compound 5 in so-
lution (see subsequent discussion).
R
R
R
R
R
R
P
P
P
S
O
S
S
S
S
Hg
Hg Hg
(III)
Hg
Hg
Hg
Hg
(I)
(II)
In the context of our interest in the coordination
chemistry of 1,1-dichalcogenophosphorus ligands, we
report here on the synthesis and spectroscopic charac-
terization of some organomercury(II) derivatives, i.e.
[2-(Me2NCH2)C6H4]HgCl (1), [2-(Me2NCH2)C6H4]Hg-
[S(S)PR2] [R ¼ Me (2), Et (3), Ph (4)], [2-(Me2NCH2)-
C6H4]Hg[S(O)PPh2] (5) and [2-(Me2NCH2)C6H4]Hg-
[S(S)P(OiPr)2] (6), as well as the crystal and molecular
structure of 1 and 4.
2. Results and discussion
2.1. Preparation
The
[2-(dimethylaminomethyl)phenyl]mercury(II)
chloride, [2-(Me2NCH2)C6H4]HgCl (1), was prepared
by reacting [2-(Me2NCH2)C6H4]Li with HgCl2 (1:1
molar ratio), in diethyl ether, at )78 ꢀC [7]. The meth-
atesis reaction between stoichiometric amounts of 1 and
the sodium or ammonium salt of the appropriate orga-
nophosphorus acid affords the isolation of [2-
(Me2NCH2)C6H4]Hg[S(S)PR2] [R ¼ Me (2), Et (3), Ph
(4)], [2-(Me2NCH2)C6H4]Hg[S(O)PPh2] (5) and [2-
(Me2NCH2)C6H4]Hg[S(S)P(OiPr)2] (6) (Scheme 1).
Compounds 1–5 were isolated as colorless crystalline
solids, while compound 6 was a viscous oil. Compounds
1, 4 and 5 are air-stable for weeks; the others decompose
to a black material within two weeks both in solution
and in the solid state. However, they were stable enough
to be characterized by multinuclear NMR. Single crys-
tals of 1 and 4 were obtained by slow difusion from a
mixture of CH2Cl2 and hexane (1/4, v/v) and the crystal
and molecular structures were determined by X-ray
diffraction.
2.3. NMR spectra
The room temperature 1H and 13C NMR spectra
of compounds 1–6 show resonances for the organic
groups bonded to mercury and phosphorus atoms, re-
spectively. The assignment of the H and 13C chemical
1
shifts for the 2-(Me2NCH2)C6H4 group according to
the numbering scheme (IV) was made using the literature
data for related organomercury(II) compounds [7–11].
NMe2
2
1
3
Hg
4
6
5
(IV)
The presence of only one singlet resonance for the
proton and carbon nuclei of the NMe2 group in com-
pounds 1–6 is consistent either with the absence of in-
tramolecular N ! Hg coordination or with a fast
conformational change of the chelate five-membered
HgC3N ring [assuming a planar (C,N)HgX core] in so-
lution, thus yielding averaged NMR resonances. The
spectra of compound 1 remained unchanged until down
to )70 ꢀC, so that no conclusion concerning possible
Hg–N interaction could be drawn.
HgCl2 + [2-(Me2NCH2)C6H4]Li
[2-(Me2NCH2)C6H4]HgCl
- LiCl
1
+ M[SXPR2]
- MCl
[2-(Me2NCH2)C6H4]Hg[S(X)PR2]
The 1H and 13C NMR spectra of compounds 2–6 also
exhibit the resonances for the organic groups attached
to the phosphorus atom with the expected splitting
2 - 6
Scheme 1.

O. Bumbu et al. / Journal of Organometallic Chemistry 689 (2004) 1172–1179
1175
pattern due to phosphorus–proton and phosphorus–
carbon couplings.
C(18a)
C(17a)
C(8a)
N(1a)
C(9a)
C(7a)
Only one singlet 31P{1H} resonance was observed in
the 31P NMR spectra of compounds 2–6. For compound
5 two isomers are possible, i.e. containing the mono-
thiophosphinato ligand connected to the metal through
the oxygen (structure V) or through sulfur atom
(structure VI). The magnitude of the observed 31P
chemical shift (d 48.5 ppm) is indicative for a structure
VI with S-monodentate monothiophosphinato moiety
[cf. d (31P) 83.5 ppm for Ph2P(S)OMe [22]; 42.8 ppm for
Ph2P(O)SMe [22]; and, for example, 64.9 ppm for
Ph3SnOSPPh2 – for a detailed discussion, see [21]]. This
behavior suggests that the coordination pattern of the
phosphorus ligand in the CHCl3 solution of compound
5 is the same as found in solid state.
C(3a)
C(4a)
C(16a)
C(10a)
C(1a)
S(1a)
Hg(1a)
P(1a)
C(11a)
C(12a)
S(2)
S(2a)
C(5)
C(12)
C(11)
C(10)
C(16)
C(13)
P(1)
Hg(1)
C(4)
C(3)
C(15)
C(14)
S(1)
C(1)
C(2)
C(21)
C(7)
C(9)
N(1)
C(17)
C(18)
C(19)
C(8)
Fig. 3. Dimer association in the crystal of 4.
Me2N
Me2N
Ph
O
Ph
S
Ph
S
Ph
O
Table 1
P
P
ꢁ
Selected interatomic distance (A) and angles (ꢀ) in 1 and 4
Hg
(V)
Hg
1 (X ¼ Cl)
2.047(6)
2.764(6)
2.319(2)
4 (X ¼ S)
2.063(6)
2.725(4)
2.3911(16)
(VI)
Hg(1)–C(1)
Hg(1)–N(1)
Hg(1)–X(1)
N(1)–C(7)
N(1)–C(8)
N(1)–C(9)
1.451(10)
1.461(10)
1.467(10)
1.452(7)
1.424(8)
1.460(7)
2.4. Crystal and molecular structure of [2-(Me2NCH2)
C6H4]HgCl (1) and [2-(Me2NCH2)-C6H4]Hg[S(S)-
PPh2] (4)
P(1)–S(1)
P(1)–S(2)
P(1)–C(10)
P(1)–C(16)
2.052(2)
1.9652(19)
1.811(5)
1.811(5)
The ORTEP diagrams for compounds 1 and 4 with
the atom numbering scheme is shown in Figs. 2 and 3,
respectively, and selected interatomic distances and an-
gles are listed in Table 1.
Hg(1)ꢀ ꢀ ꢀS(2a)
3.102(2)
C(1)–Hg(1)–X(1)
C(1)–Hg(1)–N(1)
X(1)–Hg(1)–N(1)
S(2a)ꢀ ꢀ ꢀHg(1)–C(1)
S(2a)ꢀ ꢀ ꢀHg(1)–N(1)
S(2a)ꢀ ꢀ ꢀHg(1)–S(1)
176.93(18)
75.0(2)
104.93(14)
169.54(16)
74.69(18)
108.11(11)
106.34(15)
82.01(10)
84.11(5)
The molecular structures of compounds 1 and 4 re-
veal some similar features with respect to the [2-
(Me2NCH2)C6H4]HgX (X ¼ Cl, S) moiety. The coordi-
nation arrangement around the mercury atom is best
C(7)–N(1)–C(8)
C(7)–N(1)–C(9)
C(8)–N(1)–C(9)
Hg(1)–N(1)–C(7)
Hg(1)–N(1)–C(8)
Hg(1)–N(1)–C(9)
110.9(6)
111.2(6)
109.8(6)
92.3(4)
111.3(5)
111.1(5)
111.2(5)
94.6(3)
C(8)
111.4(4)
120.1(4)
106.5(4)
121.0(4)
C(9)
S(2)–P(1)–S(1)
C(10)–P(1)–C(16)
115.98(9)
106.3(2)
N(1)
C(7)
C(3)
Hg(1)–S(1)–P(1)
Hg(1)ꢀ ꢀ ꢀS(2a)–P(1a)
95.53(7)
92.78(7)
C(2)
C(1)
C(4)
described as T-shaped due to the intramolecular
N ! Hg interaction, with the electronegative X atom
trans to the aromatic carbon attached to mercury [C(1)–
Hg(1)–Cl(1) 176.93(18)ꢀ in 1, and C(1)–Hg(1)–S(1)
Hg(1)
Cl(1)
C(5)
C(6)
ꢁ
169.54(16)ꢀ in 4]. The Hg(1)–N(1) distances [2.764(6) A
Fig. 2. ORTEP representation at 30% probability and atom numbering
scheme for the (k-S)-1 isomer.
ꢁ
in 1, and 2.725(4) A in 4] are considerably shorter that

1176
O. Bumbu et al. / Journal of Organometallic Chemistry 689 (2004) 1172–1179
the sum of the van der Waals radii for Hg and N
ꢁ
vdW(Hg,N) 3.05 A] [12]; they are intermediate
consistent with P–S single and P@S double bonds [P(1)–
S(1) 2.052(2) A, P(1)–S(2) 1.965(2) A; cf. Ph2P(S)SH
P
ꢁ ꢁ
[
between the values of 2.89(1) A for [2-(Me2NCH2)-
ꢁ
ꢁ
ꢁ
[24]: P–S 2.077(1) A and P@S 1.954(1) A], although the
sulfur atom doubly bonded to phosphorus is bridging
weakly a metal atom of a neighboring molecule. Similar
ꢁ
C6H4]2Hg [8] and 2.65(1) A in (S)-[2-{Me2NC(Me)H}-
ꢁ
C6H4]HgCl [10], 2.69(1) A in (S)C(R)Hg-[2-{Me2NC-
ꢁ
(Me)H}C10H6]HgCl [11] or 2.694(8) A in [2-(2-pyr-
idyl)phenyl-(C,N)]Hg[S(S)PCy2] [19]. The Hg(1)–Cl(1)
ꢁ
distance of 2.319(2) A in 1 is similar to those observed
for the related (S)-[2-{Me2NC(Me)H}C6H4]HgCl
ꢁ
phosphorus–sulfur distances [2.067(4), 1.963(4) A] were
also found for the monomeric [2-(2-pyridyl)phenyl-
(C,N)]Hg[S(S)PCy2] [19].
ꢁ
[2.323(3) A] [10] and (S)C(R)Hg-[2-{Me2NC(Me)H}-
ꢁ
C10H6]HgCl [2.330(4) A] [11]. In 4 the Hg(1)–S(1) bond
3. Conclusions
ꢁ
length [2.391(2) A] is slightly longer than in [2-(2-pyr-
ꢁ
idyl)phenyl-(C,N)]Hg[S(S)PCy2] [2.365(3) A] [19], a be-
The substitution of the Cl atom in [2-(Me2NCH2)-
C6H4]HgCl (1) by a potential bidentate ligand as the
[S(S)PPh2]ꢁ group in [2-(Me2NCH2)C6H4]Hg[S(S)PPh2]
(4) does not influence the intramolecular coordination of
the nitrogen atom of the CH2NMe2 pending arm to the
metal centre. The distorted T-shaped coordination ge-
ometry of the (C,N)HgX (X ¼ Cl, S) core is preserved in
the molecular unit of both compounds and the mercury
atom acts as a stereocenter. Differences in the associa-
tion degree in the crystal were noted, i.e. discrete mo-
nomeric enantiomers for 1 and dimers associations of
(d-R)–(k-S) isomers through weak intermolecular
Hgꢀ ꢀ ꢀS interactions for 4.
havior which is consistent with the asymmetric bridging
pattern in the former compound (see subsequent dis-
cussion) in contrast to the monodentate nature of the
dithio ligand in the second one.
The distortion of the three-coordinate (C,N)HgX
core from the ideal T-shaped arrangement is mainly due
to the restrictions imposed by the formation of the
C3NHg ring, the small bite of the C,N-bidentate organic
ligand being reflected in the magnitude of the C(1)–
Hg(1)–N(1) angle [75.0(2)ꢀ and 74.69(18)ꢀ in 1 and 4,
respectively].
As suggested previously by Nelson and co-workers
[10,11], the Hg atom in the title compounds can be
considered a stereocenter in solid state: the metal atom
4. Experimental
ꢁ
deviates from the C(1)N(1)X(1) plane by 0.058 A in 1
ꢁ
and 0.190 A in 4, and the sum of the three angles around
4.1. Materials and procedures
Hg is less (356.9ꢀ in 1, and 352.3ꢀ in 4, respectively) than
360ꢀ as expected for a planar structure. The molecules
are thus pyramidal, with the metal atom in the apex and
three different substituents on mercury describing the
triangular base. The chelate, five-membered C3NHg ring
is not planar, but folded along the Hg(1)ꢀ ꢀ ꢀCmethylene axis
(HgC3/HgCN dihedral angle: 41.1ꢀ in 1, and 39.9ꢀ in 4,
All manipulations were carried out under vacuum
or argon by Schlenk techniques. Solvents were dried
and freshly distilled prior to use. Mercury(II) dichlo-
ride, N,N-dimethylbenzylamine and butyllithium were
commercially available. The other starting materials
were prepared according to the literature methods:
ꢁ
respectively), with the nitrogen atom 0.819 A (1) and
[2-(Me2NCH2)C6H4]Li
[25],
Na[S2PMe2] ꢀ 2H2O
[26], Na[S2PEt2] ꢀ 2H2O [27], NH4[S2P(OiPr)2] [28],
NH4[S2PPh2] [29] and NH4[OSPPh2] [30,31]. Infrared
spectra were recorded in the range 4000–250 cmꢁ1 as
ꢁ
0.788 A (4) out from the best plane of the rest of the
atoms. This induces a second source of chirality. Indeed,
both compounds 1 and 4 crystalize as racemates. The
molecular structure of the k-S isomer of 1 is shown in
Fig. 2 [assuming the priority numbers 1 (Cl, S), 2 (N), 3
(C) and 4 (the apex of the pyramid)] [23]. The crystal of
1 consists of discrete monomeric molecular enantiomers
separated by normal van der Waals distances (the closer
1
KBr pellets on a Jasco FT/IR-615 instrument. The H,
13C and 31P NMR spectra were recorded at room tem-
perature on a VARIAN GEMINI 300S instrument op-
erating at 299.5, 75.4 and 121.4 MHz, respectively, using
solutions in dried CDCl3. The chemical shifts are
reported in ppm relative to TMS and H3PO4 85%,
respectively.
ꢁ
intermolecular Hgꢀ ꢀ ꢀCl distance, 3.575(3) A, is larger
P
than the sum of the van der Waals radii, vdW(Hg,Cl)
ꢁ
3.4 A [12]). For compound 4 the crystal contains dimers
(Fig. 3) between pairs of (d-R)–(k-S) isomers connected
through weak intermolecular Hgꢀ ꢀ ꢀS(@P) interactions
4.2. Preparation of [2-(dimethylaminomethyl)phenyl]-
mercury(II) chloride, [2-(Me2NCH2)C6H4]HgCl (1)
ꢁ
[Hg(1)ꢀ ꢀ ꢀS(2a) 3.102(2) A; cf. the sum of the van der
P
ꢁ
Waals radii, vdW(Hg,S) 3.3 A] [12] in a similar way as
The compound was prepared from [2-(Me2NCH2)-
C6H4]Li (4.52 g, 0.032 mol) and HgCl2 (8.70 g, 0.032
mol) in diethyl ether according to the literature method
[7]. It was crystallized from hot hexane to give of 1 as
colorless crystals. Yield: 10.1 g (85%), m.p. 76–77 ꢀC
found for the dimeric [MeHg{S(S)PPh2}]2 [Hgꢀ ꢀ ꢀS
3.152(3)] [15].
With respect to the dithiophosphinato ligand in
compound 4 the phosphorus–sulfur bond distances are

O. Bumbu et al. / Journal of Organometallic Chemistry 689 (2004) 1172–1179
1177
1
2
(dec.) (lit. [7]: 73 ꢀC). H NMR: d 2.33s (6H, N–CH3),
3.47s (2H, –CH2–, JHgH 13.2 Hz), 7.23m (3H, H3;4;5),
194.4 Hz). 13C NMR: d 7.59d (P–CH2–CH3, JPC 4.6
Hz), 33.57d (P–CH2–CH3, JPC 50.4 Hz), 45.07s (N–
4
1
7.45m (1H, H6, JHgH 207.7 Hz); 13C NMR: d 44.54s
(N–CH3, JHgC 10.3 Hz), 64.56s (–CH2–, JHgC 103.0
CH3, JHgC 9.2 Hz), 65.42s (–CH2–, JHgC 96.2 Hz),
4
3
5
3
5
3
3
127.20s (C5, JHgC 199.2 Hz), 128.06s (C4, JHgC 27.5
3
4
3
2
Hz), 127.44s (C5, JHgC 215.2 Hz), 128.61s (C4, JHgC
3
Hz), 128.82s (C3, JHgC 160.3 Hz), 137.32s (C6, JHgC
132.8 Hz), 144.45s (C2), 156.65s (C1). 31P NMR: d 85.0s
(1JPC 50.7 Hz).
34.3 Hz), 129.02s (C3, JHgC 164.9 Hz), 137.18s (C6,
2JHgC 139.7 Hz), 143.82s (C2), 149.20s (C1).
4.3. Preparation of [2-(Me2NCH2)C6H4]Hg[S(X)PR2]
4.3.3. [2-(Me2NCH2)C6H4]Hg[S(S)PPh2] (4)
Anal. Found: C, 43.1; H, 3.8; N, 2.3. Calc. for
C21H22HgNPS2: C, 43.2; H, 3.8; N, 2.4%. IR (cmꢁ1):
Mixtures of [2-(Me2NCH2)C6H4]HgCl and the ap-
propriate salt, M[SXPR2] (1:1 molar ratio) in 40 ml di-
1
650s [mas (PS2)], 546v [ms (PS2)]. H NMR: d 2.22s (6H,
chloromethane were stirred for 18
h
at room
N–CH3), 3.41s (2H, –CH2–, 4JHgH 13.2 Hz), 7.20m (3H,
H3;4;5), 7.46m (7H, H6 + P–C6H5-meta + para), 8.06dm
temperature and then filtered to remove the resulting
alkali or ammonium chloride. The filtrate was evapo-
rated under reduced pressure and an oily product was
obtained. After stirring for 30 min. with n-hexane, a
white solid deposited. It was separated by filtration,
washed with n-hexane and dried in vacuum. Details of
the preparations and melting points are given in Table 2.
Microanalysis (C, H, N) and NMR spectra are consis-
tent with the given composition of the isolated products.
3
(4H, P–C6H5-ortho, JPH 14.8 Hz). 13C NMR: d 44.92s
(N–CH3), 65.33s (–CH2–, JHgC 98.5 Hz), 127.24s (C5,
3
4
3JHgC 201.5 Hz), 128.11s (C4, JHgC 32.0 Hz), 128.31d
3
3
(P–C6H5-meta, JPC 13.7 Hz), 128.84s (C3, JHgC 160.3
Hz), 130.72d (P–C6H5-ortho, 2JPC 11.6 Hz), 131.10d (P–
4
2
C6H5-para, JPC 3.4 Hz), 137.30s (C6, JHgC 135.1 Hz),
1
139.65d (P–C6H5-ipso, JPC 82.4 Hz), 144.39s (C2),
156.50s (C1). 31P NMR: d 65.5s (1JPC 81.9 Hz).
4.3.1. [2-(Me2NCH2)C6H4]Hg[S(S)PMe2] (2)
Anal. Found: C, 28.6; H, 3.7; N, 3.2. Calc. for
4.3.4. [2-(Me2NCH2)C6H4]Hg[S(O)PPh2] (5)
Anal. Found: C, 44.3; H, 3.7; N, 2.5. Calc. for
C21H22HgNOPS: C, 44.4; H, 3.9; N, 2.4%. IR (cmꢁ1):
1165vs [m(PO)], 575vs [m(PS)]. 1H NMR: d 2.26s (6H, N–
CH3), 3.47s (2H, –CH2–), 7.20m (3H, H3;4;5), 7.35m
(1H, H6), 7.45m (6H, P–C6H5-meta + para), 7.95ddd
1
C11H18HgNPS2: C, 28.7; H, 3.9; N, 3.1%. H NMR: d
2.16d (6H, P–CH3, JPH 13.2 Hz), 2.37s (6H, N–CH3),
2
4
3.44s (2H, –CH2–, JHgH 13.2 Hz), 7.20m (3H, H3;4;5),
3
4
3
7.49dd (1H, H6, JHH 6.6, JHH 1.6, JHgH 196.6 Hz).
1
13C NMR: d 32.18d (P–CH3, JPC 53.8 Hz), 45.01s (N–
CH3, JHgC 9.2 Hz), 65.25s (–CH2–, JHgC 98.5 Hz),
(4H, P–C6H5-ortho, JHH 7.1, JHH 1.7, JPH 13.2 Hz).
13C NMR: d 44.49s (N–CH3), 65.04s (–CH2–, 3JHgC 96.2
Hz), 127.35s (C5), 128.26s (C4), 128.29d (P–C6H5-meta,
3JPC 13.7 Hz), 128.99s (C3), 130.67d (P-C6H5-ortho,
3
4
3
5
3
3
4
127.27s (C5, JHgC 201.5 Hz), 128.17s (C4, JHgC 29.8
3
2
Hz), 128.88s (C3, JHgC 160.3 Hz), 137.32s (C6, JHgC
135.1 Hz), 144.40s (C2); the resonance for C1 was not
observed. 31P NMR: d 63.2s.
4
2JPC 11.5 Hz), 131.30d (P–C6H5-para, JPC 3.4 Hz),
2
137.30s (C6, JHgC 132.8 Hz), 139.15d (P–C6H5-ipso,
1JPC 105.4 Hz); the resonances for C1 and C2 were not
observed. 31P NMR: d 48.5s.
4.3.2. [2-(Me2NCH2)C6H4]Hg[S(S)PEt2] (3)
Anal. Found: C, 32.2; H, 4.4; N, 2.7. Calc. for
1
C13H22HgNPS2: C, 32.0; H, 4.5; N, 2.9%. H NMR: d
4.3.5. [2-(Me2NCH2)C6H4]Hg[S(S)P(OiPr)2] (6)
Anal. Found: C, 32.7; H, 4.7; N, 2.5. Calc. for
3
3
1.39dt (6H, P–CH2–CH3, JHH 7.7, JPH 21.4 Hz),
2.13dq (4H, P–CH2–CH3, 3JHH 7.7, 2JPH 10.7 Hz), 2.36s
(6H, N–CH3), 3.44s (2H, –CH2–, 4JHgH 13.2 Hz), 7.21m
1
C15H26HgNO2PS2: C, 32.9; H, 4.9; N, 2.6%. H NMR:
3
d 1.42d [12H, P–OCH(CH3)2, JHH 6.0 Hz], 2.39s (6H,
N–CH3), 3.50s (2H, –CH2–), 4.92dh [2H, P–
3
4
3
(3H, H3;4;5), 7.51dd (1H, H6, JHH 7.5, JHH 1.6, JHgH
Table 2
Preparation data and m.p. for R0Hg[S(X)PR2] [R0 ¼ 2-(Me2NCH2)C6H4–] derivatives
Product [yield: g (%)]
m.p. (ꢀC)
Starting materials
R0HgCl (g (mmol))
M[SXPR2] (g (mmol))
0.222 (0.6)
0.222 (0.6)
0.222 (0.6)
0.222 (0.6)
0.222 (0.6)
Na[S2PMe2] ꢀ 2H2O 0.110 (0.6)
Na[S2PEt2] ꢀ 2H2O 0.125 (0.6)
NH4[S2PPh2] 0.160 (0.6)
[2-(Me2NCH2)C6H4]Hg[S(S)PMe2] (2) 0.179 (65)
[2-(Me2NCH2)C6H4]Hg[S(S)PEt2] (3) 0.208 (71)
[2-(Me2NCH2)C6H4]Hg[S(S)PPh2] (4) 0.252 (72)
[2-(Me2NCH2)C6H4]Hg[S(O)PPh2] (5) 0.225 (66)
[2-(Me2NCH2)C6H4]Hg[S(S)P(OiPr)2] (6) 0.25 (76)
97
83
121
89 (dec.)
NH4[SOPPh2] 0.150 (0.6)
NH4[S2P(OiPr)2] 0.138 (0.6)
a
–
a Viscous oil.

1178
O. Bumbu et al. / Journal of Organometallic Chemistry 689 (2004) 1172–1179
Table 3
X-ray crystal data and structure refinement for 1 and 4
1
4
Empirical formula
Formula weight
T (K)
C9H12ClHgN
370.24
297(2)
C42H44Hg2N2P2S4
1168.19
297(2)
ꢁ
k (A)
0.71073
Monoclinic
P21=c
0.71073
Triclinic
Crystal system
Space group
Unit cell dimension
ꢂ
P1
ꢁ
a (A)
5.838(3)
13.118(6)
13.886(6)
9.451(3)
10.943(3)
ꢁ
b (A)
ꢁ
c (A)
11.128(3)
77.450(4)
a (ꢀ)
b (ꢀ)
c (ꢀ)
93.648(9)
80.274(4)
78.596(4)
1091.7(5)
3
ꢁ
V (A )
1061.3(9)
4
2.317
Z
1
1.777
Dcalc (g cmꢁ3
)
Absorption coefficient (mmꢁ1
F ð000Þ
)
14.702
680
7.319
564
Crystal size (mm)
h range for data collection (ꢀ)
Reflections collected
0.20 · 0.20 · 0.34
2.1–26.4
8378
0.28 · 0.18 · 0.07
1.9–25.7
8332
Independent reflections (Rint
Data/restraints/parameters
Goodness-of-fit on F 2
)
2169 (0.042)
2169/0/111
1.02
4106 (0.0386)
4106/0/237
1.037
Final R indices [F 2 > 2rðF 2Þ]
R1 ¼ 0:0324, wR2 ¼ 0:0630
R1 ¼ 0:0472, wR2 ¼ 0:0677
0.61 and )0.84
R1 ¼ 0:0342, wR2 ¼ 0:0725
R1 ¼ 0:0391, wR2 ¼ 0:0746
1.094 and )0.986
R indices (all data)
Largest difference peak and hole (e A
ꢁ3
ꢁ
)
3
3
OCH(CH3)2, JHH 6.6, JPH 12.6 Hz], 7.22m (3H,
3
tively, to which they were attached. The drawings were
created with the DIAMOND program [35].
3
H
3;4;5), 7.49d (1H, H6, JHH 6.3, JHgH 197.8 Hz).13C
3
NMR: d 23.81d [P–OCH(CH3)2, JPC 4.6 Hz], 44.80s
(N–CH3), 65.31s (–CH2–, JHgC 98.5 Hz), 73.20d (P–
OCH(CH3)2, 2JPC 6.9 Hz), 127.41s (C5, 3JHgC 197.0 Hz),
3
5. Supplementary material
4
3
128.24s (C4, JHgC 32.1 Hz), 129.17s (C3, JHgC 160.4
2
Hz), 137.83s (C6, JHgC 132.8 Hz), 144.40s (C2);
the resonance for C1 was not observed. 31P NMR: d
97.4s.
Crystallographic data for the structural analysis have
been deposited with the Cambridge Crystallographic
Data Centre CCDC Nos. 215788 for compound 1 and
215787 for compound 4. Copies of the information may
be obtained free of charge from The Director, CCDC,
12 Union Road, Cambridge CB2 1EZ, UK (fax: +44-
1223-336033; e-mail: deposit@ccdc.cam.ac.uk or www:
http://www.ccdc.cam.ac.uk).
4.4. X-ray structure determination
Colourless, block crystals of [2-(Me2NCH2)C6H4]
HgCl (1) and [2-(Me2NCH2)C6H4]Hg[S(S)PPh2] (4)
were mounted on a cryoloop. Data collection and pro-
cessing was carried out using a Bruker SMART APEX
system (Babes-Bolyai University, Cluj-Napoca). Cell
refinement gave cell constants corresponding to a
monoclinic cell for 1 and a triclinic cell for 4, whose
dimensions are given in Table 3 along with other ex-
perimental parameters.
An absorption correction was applied [32]. The
structures were solved by direct methods [32,33] and
refined using SHELX-97 [32,34]. All of the non-hydrogen
atoms were treated anisotropically. Hydrogen atoms
were included in idealized positions with isotropic
thermal parameters set at 1.2 and 1.5 times that of the
aromatic/methylene and methyl carbon atom, respec-
Acknowledgements
This work was supported by the National University
Research Council of Romania (CNCSIS–TD-5-153-
2003). O.B. acknowledges a Socrates/Erasmus fellow-
ship and the University of Zaragoza for providing
research facilities and financial support during a three-
month research stay. We thank the National Center for
X-Ray Diffraction (‘‘Babes-Bolyai’’ University, Cluj-
Napoca) for support of the single-crystal X-ray diffrac-
tion studies.

O. Bumbu et al. / Journal of Organometallic Chemistry 689 (2004) 1172–1179
1179
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