Triarylphosphanes with 2-(Et2NCH2)C6H4 groups. Copper(I) complexes and oxidation derivatives of type EP(C6H4CH2NEt2-2)nPh3-n (E = S, Se; n = 1,2)

Article abstract of DOI:10.1016/j.ica.2017.09.044

The triarylphosphanes P(C₆H₄CH₂NEt₂-2)_nPh_3-n [n = 1 (1), 2 (2)] were obtained by reacting Ph₂PCl or PhPCl₂ with [2-(Et₂NCH₂)C₆H₄]Li in a 1:1 and a 1:2 molar ratio, respectively. Further oxidation with elemental sulfur or elemental selenium powder resulted in the triorganophosphane chalcogenides EP(C₆H₄CH₂NEt₂-2)_nPh_3-n [E = S, n = 1 (3), 2 (5); E = Se; n = 1 (4), 2 (6)]. The copper(I) complexes [CuCl{P(C₆H₄CH₂NEt₂-2)_nPh_3-n}] [n = 1 (7), 2 (8)] were prepared by the reactions between the triarylphosphanes 1 and 2 with CuCl in a 1:1 molar ratio. The new species were investigated in solution by NMR spectroscopy. The single crystal X-ray diffraction studies revealed a monomeric structure for the triorganophosphane sulphides 3 and 5, while the copper(I) complexes 7 and 8 form dimers by bridging chlorine atoms. In both copper complexes the phosphane ligands behave as C,N chelating moieties. For compound 8 the two C₆H₄CH₂NEt₂-2 groups are equivalent in solution, while in solid state only for one of them the N→Cu intramolecular interaction was observed.

Full text of DOI:10.1016/j.ica.2017.09.044

Accepted Manuscript
Triarylphosphanes with 2-(Et2NCH2)C6H4 groups. Copper(I) complexes and
oxidation derivatives of type EP(C6H4CH2NEt2-2)nPh3-n (E = S, Se; n = 1,2)
Razvan Suteu, Sergiu Shova, Anca Silvestru
PII:
S0020-1693(17)31140-4
http://dx.doi.org/10.1016/j.ica.2017.09.044
ICA 17903
DOI:
Reference:
Inorganica Chimica Acta
To appear in:
Received Date:
Revised Date:
Accepted Date:
22 July 2017
15 September 2017
15 September 2017
Please cite this article as: R. Suteu, S. Shova, A. Silvestru, Triarylphosphanes with 2-(Et2NCH2)C6H4 groups.
Copper(I) complexes and oxidation derivatives of type EP(C6H4CH2NEt2-2)nPh3-n (E = S, Se; n = 1,2), Inorganica
Chimica Acta (2017), doi: http://dx.doi.org/10.1016/j.ica.2017.09.044
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Inorganica Chimica Acta
Triarylphosphanes with 2-(Et2NCH2)C6H4 groups. Copper(I) complexes and
oxidation derivatives of type EP(C6H4CH2NEt2-2)nPh3-n (E = S, Se; n = 1,2).
Razvan Suteu,a Sergiu Shovab and Anca Silvestrua,*
a Centre of Supramolecular Organic and Organometallic Chemistry, Department of Chemistry, Faculty of
Chemistry and Chemical Engineering, Babeş-Bolyai University, Str. Arany Janos 11, RO-400028 Cluj-
Napoca, Romania; E-mail: ancas@chem.ubbcluj.ro
b ''Petru Poni'' Institute of Macromolecular Chemistry, Aleea Grigore Ghica Vodă 41A, 700487, Iași, Romania
Abstract
The triarylphosphanes P(C6H4CH2NEt2-2)nPh3-n [n = 1 (1), 2 (2)] were obtained by reacting
Ph2PCl or PhPCl2 with [2-(Et2NCH2)C6H4]Li in a 1:1 and a 1:2 molar ratio, respectively. Further
oxidation with elemental sulfur or elemental selenium powder resulted in the triorganophosphane
chalcogenides EP(C6H4CH2NEt2-2)nPh3-n [E = S, n = 1 (3), 2 (5); E = Se; n = 1 (4), 2 (6)]. The
copper(I) complexes [CuCl{P(C6H4CH2NEt2-2)nPh3-n}] [n = 1 (7), 2 (8)] were prepared by the
reactions between the triarylphosphanes 1 and 2 with CuCl in a 1:1 molar ratio. The new species were
investigated in solution by NMR spectroscopy. The single crystal X-ray diffraction studies revealed a
monomeric structure for the triorganophosphane sulphides 3 and 5, while the copper(I) complexes 7
and 8 form dimers by bridging chlorine atoms. In both copper complexes the phosphane ligands
behave as C,N chelating moieties. For compound 8 the two C6H4CH2NEt2-2 groups are equivalent in
solution, while in solid state only for one of them the N→Cu intramolecular interaction was observed.
Key words: P/N triarylphosphanes; triarylphosphane chalcogenides; copper(I) complexes; solution
behaviour; solid state structure;

1.
Introduction
Heteropolydentate ligands bearing both phosphorus and nitrogen as donor atoms, so named
P/N ligands, are still of high interest, due to their coordination ability towards different transition
metals and the potential of the resulted metal complexes in catalysis [1-3]. The combination of the π-
acceptor character of phosphorus and the σ-donation ability of nitrogen results in the stabilization of
the metal center in a low oxidation state and also in an increased availability for oxidative addition
reactions [4]. Different organic groups, i.e. amino, imino, pyridine, etc., were used in order to allow a
fine tuning of the electronic properties of various P/N ligands, thus allowing to design appropriate
compounds for specific catalytic processes [5,6]. Triorganophosphanes bearing aryl groups with
pendant arms with nitrogen donor atoms, i.e. 2-(Me2NCR1R2)C6H4 (R1 = H, R2 = H, Me) [7], [2-
(Me2NCR1R2)]2C6H3 (R1 = R2 = H) [8], were described and used as ligands for different transition
metals. In such metal complexes, besides the stabilization effect of the P→M interaction, the presence
of nitrogen in one or more pendant arms attached to the organic groups in the R3P ligand usually
results in additional N→M intramolecular coordination.
Copper compounds stabilized by triarylphosphanes proved to be promising candidates as
active species in catalysis, i.e. in hydroboration [9], hydrogenation [10], carbene insertion into the N–
H bond [11], etc., and, based on their photoluminescent properties, in the design of different types of
sensors [12,13].
In copper complexes with the PN3 ligand P(C6H4CH2NMe2-2)3 the phosphane was observed to
act as a chelating either P,N- [14,15] or P,N,N- [16,17] moiety in the mononuclear species
[CuX{P(C6H4CH2NMe2-2)3}] (X = Cl, I). The third pendant arm was involved in coordination to the
‾
metal as a chelating moiety in the ionic [{2-(Me2NCH2)C6H4}3PCu]+ ClO4 [16] or the dinuclear
[CuX{P(C6H4CH2NMe2-2)3}]2 (X = Cl, Br) [15,18], while in other species it remained dangling [17].
We have previously reported some copper(I) compounds of type [CuX{P(C6H4CH2NMe2-2)nPh3-n}]
(n = 0 – 2; X = Cl, I) and we observed a chelating P,N- behaviour in the mononuclear
[CuCl{PPh2(C6H4CH2NMe2-2)}] and the dinuclear [CuI{P(C6H4CH2NMe2-2)Ph2}]2. For the
compound [CuCl{P(C6H4CH2NMe2-2)2Ph}] were found two independent molecules in the
asymmetric unit, with a different coordination behaviour of the triarylphosphane in each of them, e.g.
in one of them both nitrogen atoms are intramolecularly interacting with copper, while in the other
molecule one nitrogen is interacting with copper and the other with phosphorus [19].

As a continuation of our interest in triarylphosphanes with organic groups bearing pendant
arms, we extended our studies upon the triarylphosphanes P(C6H4CH2NEt2-2)nPh3-n (n = 1, 2) and we
report here their synthesis and structural characterization, as well as the Cu(I) complexes of type
[CuCl{P(C6H4CH2NEt2-2)nPh3-n}]. In addition, the oxidation products E=P(C6H4CH2NEt2-2)nPh3-n (E
= S, Se) are also discussed.
2.
2.1. General methods
The intermediates 2-(Et2NCH2)C6H4Br and [2-(Et2NCH2)C6H4]Li were prepared
Experimental
n
according to literature procedures [20] and the starting materials, i.e. BuLi, HNEt2, 2-
bromobenzyl bromide, PhPCl2, Ph2PCl, elemental S and Se powders and CuCl were purchased
from Sigma Aldrich and used without further purification. All manipulations involving air
sensitive compounds were carried out under argon, by using Schlenk techniques. Solvents were
dried and distilled prior to use.
13
31
77
Multinuclear (1H, C, P and Se) NMR spectra were recorded at room temperature in
CDCl3 on a BRUKER DRX 400 instrument, operating at 400.13, 100.61, 161.92 and 76.28
13
MHz, respectively. The chemical shifts (δ) are reported in ppm relative to TMS (1H and C),
1
13
H3PO4 85% (31P) and Me2Se (77Se). The H and C chemical shifts were assigned based on 2D
NMR experiments using standard BRUKER XWIN-NMR pulse sequencies. The NMR spectra
were processed using the MestReC and MestReNova software [21]. The mass spectra were
measured on a LTQ-OrbitrapXL mass spectrometer equipped with a standard ESI/APCI source.
2.2. Syntheses
Synthesis of P(C6H4CH2NEt2-2)Ph2 (1)
PPh2Cl (3.5 mL, ρ = 1.2 g/mL, 19.0 mmol) in THF (5 mL) was added dropwise to a
solution of [2-(Et2NCH2)C6H4]Li (3.21 g; 19.0 mmol) in THF (25 mL) at 0 oC. The reaction
mixture was stirred at 0 oC for 2 h, then it was allowed to reach the room temperature and the
solvent was removed under vacuum. The remaining oily product was extracted in hexane. The
solid residue was filtered off and from the clear solution the solvent was removed under vacuum
to give the title compound as a yellowish oil. Yield: 4.7 g (71%). 1H NMR (CDCl3): 0.89 (t, 6H,

CH2-CH3, 3JHH 7.16 Hz), 2.47 (q, 4H, CH2-CH3, 3JHH 7.11 Hz), 3.82 (s, br., 2H, CH2N), 6.92 (dd,
3
3
1H, H6, 3JHH 4.42, JPH 7.51 Hz), 7.16 (t, 1H, H5, JHH 7.61 Hz), 7.27-7.42 (m, 10H, P-C6H5-
ortho+meta+para, + 1H H4), 7.62 (m, 1H, H3). 13C NMR (CDCl3): 11.53 (s, CH2-CH3), 46.42 (s,
3
3
CH2-CH3), 57.11 (d, CH2N, JPC 19.8 Hz), 127.36 (s, C5), 128.95 (d, C6H5-meta, JPC 8.2 Hz),
4
3
128,92 (d, C6H5-para, JPC 2.54 Hz), 129.08 (s, C4), 129.73 (d, C3, JPC 5.83 Hz), 134.33 (d,
1
C6H5-ortho, 2JPC 19.8 Hz), 134.49 (br, C6), 137.02 (d, C1, JPC 14.4 Hz), 138.67 (d, C2, 2JPC 11.2
Hz), 146.04 (d, C6H5-ipso, 1JPC 22.9 Hz). 31P NMR (CDCl3): -16.03 (s).
P(C6H4CH2NEt2-2)2Ph (2) was prepared similarly, from PPhCl2 (2 mL, ρ = 1.32 g/mL, 14.7
mmol) and [2-(Et2NCH2)C6H4]Li (4.97 g, 29.4 mmol), as a yellowish oil. Yield: 4.8 g (76%). 1H
3
3
NMR (CDCl3 ): 0.85 (t, 12H, CH2-CH3, JHH 7.16 Hz), 2.42 (q, 8H, CH2-CH3, JHH 7.12 Hz),
2
4
3.71 (ABX spin system with δA 3.69 and δB 3.72, 4H, CH2N, JHH 14.15, JPH 3.11 Hz), 6.78
3
(ddd, 2H, H6 JHH 6.53, 4JHH 1.12, 3JPH 4.3 Hz), 7.09 (t, 2H, H5, 3JHH 7.4 Hz), 7.19-7.21 (m, 2H,
H5), 7.27-7.31 (m, 5H C6H5-ortho+meta+para + 2H H4), 7.59 (dd, 2H, C6H5-ortho, 3JHH 6.86,
13
3
4JHH 4.09 Hz). C NMR (CDCl3): 11.41 (s, CH2-CH3), 46.38 (s, CH2-CH3), 56.00 (d, JPC 21.4
3
4
Hz), 126.68 (s, C5), 128.36 (d, C6H5-meta, JPC 17.4 Hz), 128.26 (d, C6H5-para, JPC 6.1 Hz),
3
128.76 (d, C3, JHH 5.34 Hz), 133.65 (s, C4), 134.98 (d, C6H5-ortho, 2JPC 20.5 Hz), 136.21 (d, C1,
2
1
1JPC 13.9 Hz), 137.58 (d, C2, JPC 9.2 Hz), 144.71 (d, C6H5-ipso, JPC 24.9 Hz). 31P NMR
(CDCl3): -25.9 s.
Synthesis of SP(C6H4CH2NEt2-2)Ph2 (3)
Elemental sulfur (0.04 g; 1.25 mmol) was added to a solution of P(C6H4CH2NEt2-2)Ph2
(2) (0.43 g; 1.25 mmol) in anhydrous THF. The reaction mixture was stirred for 48 h, then it was
filtered to remove traces of unreacted sulfur. The solvent was removed from the filtrate under
vacuum and the obtained solid was washed with n-hexane. The title product was obtained as a
pale yellow solid. Yield: 0.34 g (72%). M.p. = 116 ⁰C. Anal. Calc. for C23H26NPS (MW 379.50):
1
C, 72.79; H, 6.91; N, 3.69; S, 8.45 %. Found: C, 72.84; H, 6.98; N, 3.65; S, 8.11%. H NMR
(CDCl3 ): 0.87 (s, br., 6H, CH2-CH3), 2.39 (s, br., 4H, CH2-CH3), 3.82 (s, br., 2H, CH2N), 6.88
3
3
(1H, dd, H6, 3JHH 7.9, JPH 15.1 Hz), 7.13 (t, 1H, H5, JHH 6.9 Hz), 7.40-7.55 (m, 6H C6H5-
3
3
meta+para + 1H H4), 7.84 (dd, 4H, C6H5-ortho, JHH 7.2 Hz, JPH 13.2 Hz), 8.1 (br., H3). 13C

NMR (CDCl3): 11.55 (s, v. br., CH2-CH3), 46.73 (s, 2H, CH2-CH3, 55.42 (s, br., CH2N), 129.39
2
3
(s, br., C5), 127.43 (d, JPC 12.1 Hz, C2), 128.60 (d, C6H5-meta, JPC 12.7 Hz), 129.21 (d, C6H5-
ipso, 1JPC 80.2 Hz), 129.29 (d, C1, 1JPC 48.3 Hz), 130.69 (d, C3, 3JPC 11.5 Hz), 131.62 (br., C6H5-
para), 131.95 (d, C4, 3JPC 9.1 Hz), 132.28 (d, C6H5-ortho, 3JHH 10.9 Hz), 132.55 (d, C6, 2JPC 11.3
Hz). 31P NMR (CDCl3): 41.45 (s, 1JPC 80.2 Hz).
Compounds 4 – 6 were prepared similarly:
SeP(C6H4CH2NEt2-2)Ph2 (4) from elemental selenium powder (0.29 g; 3.7 mmol) and [2-
o
(Et2NCH2)C6H4]Ph2P (1.29 g; 3.7 mmol). Yield: 1.12 g (71%). M.p. = 129 C. Anal. Calc. for
C23H26NPSe (MW 426.39): C, 64.79; H, 6.15; N, 3.28 %. Found: C, 64.82; H, 6.33; N, 3.42 %.
1H NMR (CDCl3): 0.89 (s, br., 6H, CH2-CH3), 2.47 (s, br., 4H, CH2-CH3), 3.87 (s, br., 2H,
CH2N), 6.85 (1H, dd, H6, 3JHH 7.1, 3JPH 15.3 Hz), 7.13 (t, 1H, H5, 3JHH 7.3 Hz), 7.3 (br., 1H, H4),
3
3
7.38-7.54 (m, 6H C6H5-meta+para + 1H H4), 7.80 (dd, 4H, C6H5-ortho, JHH 8.1 Hz, JPH 13.6
Hz), 8.2 (br., H3). 13C NMR (CDCl3): 11.32 (s, br., CH2-CH3), 46.71 (s, 2H, CH2-CH3, 55.17 (s,
3
2
br., CH2N), 126.57 (d, br., C5, JPC 8.2 Hz), 127.72 (d, C2, JPC 12.7 Hz), 128.67 (d, C6H5-meta
1
1
3JPC 13.4 Hz), 129.18 (d, C1, JPC 55.2 Hz), 130.89 (d, C6H5-ipso, JPC 75.6 Hz), 131.31 (d, C3,
3JPC 9.6 Hz), 131.77 (d, C6H5-para, 4JPC 2.4 Hz), 132.02 (s, br., C4), 132.45 (d, C6, 2JPC 12.2 Hz),
132.85 (d, C6H5-ortho, 3JHH 10.5 Hz). 31P NMR (CDCl3): 30.83 (s, 1JPC 75.8 Hz, 1JPSe 722.2 Hz).
77Se NMR (CDCl3): -260.1 (d, br., 1JPSe 728.7 Hz).
SP(C6H4CH2NEt2-2)2Ph (5) from elemental sulfur (0.10 g; 3.1 mmol) and P(C6H4CH2NEt2-
2)2Ph (1.35 g; 3.1 mmol). Yield: 1.18 g (82%). M.p. = 102 oC. Anal. Calc. for C28H37N2PS (MW
464.65): C, 72.38; H, 8.03; N, 6.03; S, 6.90 %. Found: C, 72.41; H, 8.15; N, 6.22; S, 6.74 %. 1H
NMR (CDCl3): 0.84 (t, 12H, CH2-CH3, 3JHH 7.16 Hz), 2.33 (q, 8H, CH2-CH3, 3JHH 7.12 Hz), 3.84
2
(AB spin system with δA 3.76 and δB 3.93, 4H, CH2N, JHH 15.2 Hz), 7.11 – 7.18 (m, 4H, H6 +
H5) 7.42 - 7.55 (m, 3H C6H5-meta+para + 2H H4), 7.74 (dd, 2H, C6H5-ortho, 3JHH 6.8, 3JPH 12.4
13
Hz), 8.04 (m, H3). C NMR (CDCl3): 12.07 (s, CH2-CH3), 46.7 (s, CH2-CH3), 56.27 (s, NCH2),
3
3
3
125.51 (d, C5, JPC 12.4 Hz ), 128.41 (d, C6H5-meta, JPC 12.5 Hz), 129.76 (d, C3, JPH 9.6 Hz),
1
4
4
130.15 (d, C1, JPC 82.3 Hz), 131.51 (d, C4, JPC 2.8 Hz), 131.64 (d, C6H5-para, JPC 2.7 Hz),

132.35 (d, C6, 2JPC 10.7 Hz), 132.5 (d, C6H5-ipso, 1JPC 83.2 Hz), 132.93 (d, C6H5-ortho, 2JPC 11.8
Hz), 146.05 (d, C2, 2JPC 8.2 Hz). 31P NMR (CDCl3): 41.2s, 1JPC 82.3 Hz.
SeP(C6H4CH2NEt2-2)2Ph (6) from elemental selenium (0.10 g, 1.3 mmol) and P(C6H4CH2NEt2-
o
2)2Ph (0.56 g; 1.3 mmol). Yield: 0.48 g (73%). M.p. = 121 C. Anal. Calc. for C28H37N2PSe
1
(MW 511.54): C, 65.74; H, 7.29; N, 5.48 %; Found: C, 65.77; H, 7.28; N, 5.45 %; H NMR
3
3
(CDCl3): 0.84 (t, 12H, CH2-CH3, JHH 7.5 Hz), 2.32 (q, 8H, CH2-CH3, JHH 7.5 Hz), 3.80 (AB
spin system, δA 3.67 and δB 3.91, 4H, CH2N, 1JHH 16.2 Hz), 7.14 – 7.25 (m, 4H H6 + H5), 7.42 -
3
3
7.54 (m, 3H C6H5-meta+para + 2H H4), 7.78 (dd, 2H, C6H5-ortho, JHH 7.5, JPH 12.1 Hz), 8.03
2
(dd., 2H H3). 13C NMR (CDCl3): 12.13 (s, CH2-CH3), 46.86 (s, CH2-CH3), 56.50 (d, NCH2, JPC
3
1
3
5.1 Hz), 126.26 (d, C5, JPC 12.3 Hz ), 128.52 (d, C1, JPC 72.3 Hz), 128.57 (d, C6H5-meta, JPC
3
1
4
13.1 Hz), 129.81 (d, C3, JPH 10.3 Hz), 131.12 (d, C6H5-ipso, JPC 74.5 Hz), 131.70 (d, C4, JPC
2.6 Hz), 131.84 (d, C6H5-para, 4JPC 2.7 Hz), 132.69 (d, C6H5-ortho, 2JPC 11.3 Hz), 133.67 (d, C6,
2
31
1
2JPC 10.5 Hz), 146.04 (d, C2, JPC 8.5 Hz). P NMR (CDCl3): 26.63 (s, 1JPC 74.6 Hz, JPSe 710.6
Hz). 77Se NMR (CDCl3): - 191.57 (d, br., 1JPSe 709.6 Hz).
Synthesis of [CuCl{P(C6H4CH2NEt2-2)Ph2}] (7)
To a solution of P(C6H4CH2NEt2-2)Ph2 (0.49 g, 1.4 mmol) in anhydrous chloroform was
added CuCl (0.14 g, 1.4 mmol). The reaction mixture was refluxed for 4 h and left under stiring
over night. The next day the solvent was removed under reduced pressure. The remaining solid
was washed with toluene, and dried under vacuum to give the title compound as a colorless
o
solid. Yield: 0.57 g (91%). M.p. = 152 C. Anal. Calc. for C23H26ClCuNP (MW 446.43): C,
61.88; H, 5.87; N, 3.14 %; Found: C, 61.63; H, 5.81; N, 3.33 %; 1H NMR (CDCl3): 1.17 (t, 6H,
CH2-CH3, 3JHH 7.5 Hz), 2.75 (d, 2H, CH2-CH3, 3JHH 7.5 Hz), 3.56 (s, 2H, CH2N), 6.89 (t, 1H, H6,
3JHH 7.8 Hz), 7.28-7.31 (m, 2H, H4 + H5), 7.36-7.43 (m, 4H P-C6H5-meta + 1H H3), 7.44-7.49
(m, 6H P-C6H5-ortho+para). 13C NMR (CDCl3): 10.91 (s, CH2-CH3), 50.09 (s, CH2-CH3,), 58.88
(d, CH2N, 3JPH 5.6 Hz), 128.99(d, C5, 3JPC 4.9 Hz), 129.26 (d, C6H5-ortho, 3JPC 10.2 Hz), 130.18
1
1
(d, C6H5-ipso, JPC 35.3 Hz), 130.37 (s, br., C3), 130.86 (s., br., C6H5-para), 131.54 (d, C1, JPC
3
2
29.5 Hz), 133.25 (s, br., C4 + C6), 134.37 (d, C6H5-meta, JPC 14.6 Hz), 139.91 (d, C2, JPC 16.6
+
Hz). 31P NMR (CDCl3): -10.93s. ESI+ MS (m/z, %): 410.11 (100) [{CuP(C6H4CH2NEt2-2)Ph2 ].

[CuCl{P(C6H4CH2NEt2-2)2Ph}] (8) was prepared silmilarly, from P(C6H4CH2NEt2-2)2Ph (0.27
g, 0.62 mmol) and CuCl (0,061 g; 0.62 mmol), as a colorless solid. Yield: 0.27 g (82%). M.p. =
o
142 C. Anal. Calc. for C28H37ClCuN2P (MW 532.59): C, 63.14; H, 7.19; N 5.26 %; Found: C,
63.31; H, 7.11; N, 5.44 %. 1H NMR (CDCl3): 0.96 (s, br., 12H, CH2-CH3), 2.57 (s, br., 4H, CH2-
CH3), 3.71 (AB spin system, δA 3.67, δB 3.74, br., 2H, CH2N, 1JHH 11.6 Hz), 6.81 (t, 2H, H6, 3JHH
13
7.6 Hz), 7.21 (t, 2H, H5, 3JHH 7.1 Hz), 7.29-7.57 (m, 5H C6H5-ortho+meta+para + 4H, H4,3. C
NMR (CDCl3): 10.72 (s, CH2-CH3), 47.79 (s, CH2-CH3), 58.23 (s, br., CH2N), 128.05 (s, C5),
3
4
129.15 (d, C6H5-ortho, JPC 11.2 Hz), 130.25 (s, br., C4), 130.28 (d, C6H5-para, JPC 8.1 Hz),
130.67 (d, C3, 3JPC 12.1 Hz), 131.61 (d, br., C4, 4JPC 7.5 Hz), 133.17 (s, br., C6), 134.84 (d, C6H5-
2
meta, JPC 17.1 Hz), 142.29 (s., br., C2) 31P NMR (CDCl3): -20.61 (s, br.). ESI+ MS (m/z, %):
531.18 (38) [CuCl{P(C6H4CH2NEt2-2)2Ph} + H+], 495.20 (100) [Cu{P(C6H4CH2NEt2-2)2Ph}+].
2.3. Crystal structure determination
For SP(C6H4CH2NEt2-2)Ph2 (3), SP(C6H4CH2NEt2-2)2Ph (5) and the copper(I)
complexes [CuCl{P(C6H4CH2NEt2-2)Ph2}] (7) and [CuCl{P(C6H4CH2NEt2-2)2Ph}] (8) X-ray
quality crystals were obtained from chloroform / n-hexane mixtures (1/4, v/v).
Block crystals of 3, 5, 7 and 8 were attached with epoxy glue on cryoloops and the data
were collected at about 200 K or at room temperature (see Table 1) on an Oxford-Diffraction
XCALIBUR E CCD diffractometer (for 3, 5 and 8) and a Bruker SMART APEX CCDC
diffractometer (for 7), using graphite-monochromated Mo-Kα radiation (λ = 0.71073 Å). The
unit cell determination and data integration were carried out using the CrysAlis package of
Oxford Diffraction [22] for 3, 5 and 8 and SADABS - Bruker/Siemens [23] for 7. The structures
were solved by direct methods using the Olex2 [24] software with the SHELXS structure
solution program (for 3, 5 and 8) or the SHELXTL Version 6.10 - 2000 (for 7) and refined by
full-matrix least-squares on F² with SHELXL-2016/4 [25]. Atomic displacements for non-
hydrogen atoms were refined using an anisotropic model. Hydrogen atoms were refined with a
riding model and a mutual isotropic thermal parameter. The carbon atoms of the ethyl groups in
compound 3 (C14, C15, C16 and C17) are disordered over two positions with a contribution of
0.56:0.44 each of them). In compound 8 the carbon atoms of one ethyl group (C25, C26, C27
and C28) are disordered over two positions as well, with a contribution of 0.62:0.38. The

positional parameters of the disordered ethyl fragments in 3 and 8 were refined in combination
with PART and SADI restrains using anisotropic/isotropic model for non-H atoms. Table 1
provides a summary of the crystallographic data together with refinement details for compounds
3, 5, 7 and 8. The drawings were created with the Diamond program [26].
Table 1. Crystal data and structure refinement for SP(C6H4CH2NEt2-2)Ph2 (3), SP(C6H4CH2NEt2-2)2Ph
(5), [CuCl{P(C6H4CH2NEt2-2)Ph2}] (7) and [CuCl{P(C6H4CH2NEt2-2)2Ph}] (8)
3
C23H26NPS
379.48
296(4)
0.71073
Monoclinic
P2(1)/c
12.907(10)
9.375(4)
18.611(11)
90
106.88(7)
90
2155(2)
4
1.170
0.231
5
C28H37N2PS
464.63
200.00(14)
0.71073
Monoclinic
P2(1)/c
8.9525(14)
22.940(2)
12.8369(14)
90
101.697(12)
90
7
C46H52Cl2Cu2N2P2
892.81
8
C28H37ClCuN2P
531.56
199.9(6)
0.71073
Monoclinic
P2(1)/c
13.7305(9)
15.9477(10)
12.7585(7)
90
103.251(6)
90
Empirical formula
Formula weight
Temperature, K
Wavelength, Å
Crystal system
Space group
a (Å)
b (Å)
c (Å)
α (°)
β (°)
294(2)
0.71073
Triclinic
P -1
9.5546(18)
10.1300(19)
12.454(2)
103.837(4)
97.059(3)
110.220(3)
1070.0(4)
1
γ (°)
Volume, Å3
Z
2581.6(5)
4
1.195
0.206
1000.0
2719.3(3)
4
1.298
0.979
1120.0
Density (calculated), g/cm3
Absorption coefficient, mm-1
F(000)
1.386
1.228
464
808
Crystal size, mm
0.16 x 0.04 x 0.02 0.20 x 0.15 x 0.03 0.39 x 0.33 x 0.28
0.15 x 0.15 x
0.04
1.52 to 25.03
θ range for data collections (o)
Reflections collected
2.40 to 24.71
6844
1.78 to 25.03
12173
1.729 to 24.997
10180
10649
Independent reflections
6845
[Rint = 0.0000]
4566
3745
[Rint = 0.0453]
4806
[Rint = 0.0567]
[Rint = 0.0630,
Refinement method
Full-matrix least-squares on F2
Data / restraints / parameters
6845 / 13 / 231
0.695
4566/1/293
1.044
3745 / 0 / 246
0.967
4806/7/289
1.033
Goodness-of-fit on F2
Final R indicies [I>2sigma(I)]
R1 = 0.0843,
wR2 = 0.1695
R1 = 0.2718,
wR2 = 0.2050
0.331 and -0.373
R1 = 0.0813,
wR2 = 0.1723
R1 = 0.1260,
wR2 = 0.1975
0.99 and -0.41
R1 = 0.0397,
wR2 = 0.0868
R1 = 0.0572,
wR2 = 0.0925
0.349 and -0.288
R1 = 0.0612,
wR2 = 0.1211
R1 = 0.0950,
wR2 = 0.1358
0.79 and -0.73
R indicies (all data)
Largest diff. peak and hole, eÅ-3
3. Results and discussion
3.1. Synthesis and spectroscopic characterization
The triaryl phosphanes P(C6H4CH2NEt2-2)nPh3-n [n = 1 (1), 2 (2)] were prepared by
reacting the lithiated derivative [2-(Et2NCH2)C6H4]Li, previously obtained in situ by the ortho
lithiation of 2-(Et2NCH2)C6H4Br, with Ph2PCl and PhPCl2, respectively, in the appropriate molar
ratio. Further oxidation with elemental sulfur or elemental selenium powder resulted in the triaryl

phosphane chalcogenides EP(C6H4CH2NEt2-2)nPh3-n [E = S, n = 1 (3), 2 (5); E = Se; n = 1 (4), 2
(6)]. The reaction of 1 and 2 with CuCl in a 1:1 molar ratio lead to the copper(I) complexes
[CuCl{P(C6H4CH2NEt2-2)nPh3-n}] [n = 1 (7), 2 (8)]. The described transformations are depicted
in Scheme 1.
Scheme 1
The triarylphosphanes 1 and 2 were isolated as yellowish oils, while the other compounds
are pale yellow (3 – 6) or colourless (7 and 8) microcrystalline solids. All compounds were
13
31
77
characterized in solution by NMR spectroscopy (1H, C, P and Se where appropriate). The
copper(I) complexes were investigated also by mass spectrometry.
The 1H and the 13C NMR spectra present the expected resonances for the organic groups
attached to phosphorus. For the compounds bearing two 2-(Et2NCH2)C6H4 groups the NMR
1
spectra suggest their equivalence in solution. The H NMR resonances of the CH2N(CH2CH3)2
moieties bring no clear evidence for an intramolecular N→P or N→Cu coordination in solution,
where such a behaviour is expected. For the triaryl phosphanes 1 and 2 a triplet and a quartet
characteristic for the ethyl protons, accompanied by a broad singlet in 1 and an ABX spin system
in 2, characteristic for the C6H4CH2N protons, are present. For the triorganophosphorus
chalcogenides 3 and 4 bearing one 2-(Et2NCH2)C6H4 group, only broad resonances were
observed in the aliphatic region, while for compounds 5 and 6, with two 2-(Et2NCH2)C6H4
groups, the resonances for the aliphatic protons are well resolved, giving rise to a triplet and a
quartet for the ethyl protons and an AB spin system for the diastereotopic C6H4CH2N protons.
This behaviour might be consistent with the more crowded environment in case of the species
bearing two groups with pendant arms. For the copper(I) complexes the resonances
corresponding to the ethyl protons in 7 are resolved in a triplet and a quartet, while those

observed for the complex 8 are broad singlets. In addition, the C6H4CH2N protons appear as a
broad singlet in 7 and an AB spin system in 8.
13
The C NMR spectra present the expected number of resonances, in most cases split as
doublets due to the coupling with phosphorus.
The 31P{H} NMR spectra present in all cases only one singlet resonance, thus being
consistent with the presence of only one species in solution. For the selenium containing species,
31
the 31P NMR resonance is accompanied by 77Se satellites determined by the P – 77Se coupling.
77
For compound 6 the Se NMR resonance could not be detected, but for compound 4 a doublet
1
was observed at δ -260.1 ppm, with a coupling constant JPSe of 728.7 Hz, almost identical to the
value found in the 31P NMR spectrum of this compound, respectively 1JPSe 722.2 Hz.
The ESI+ MS spectra of the copper(I) complexes present the peak characteristic for the
ion [M – Cl]+ at m/z 410.11 in 7 and at m/z 495.20 in 8 as base peak. Only in compound 8 was
observed a peak at m/z 531.18 with a lower intensity (38 %), corresponding to the pseudo-
molecular ion [{P(C6H4CH2NEt2-2)2Ph}CuCl + H+].
3.2. Single-crystal X-ray diffraction studies
3.2.1. Crystal and molecular structure of SP(C6H4CH2NEt2-2)Ph2 (3) and
SP(C6H4CH2NEt2-2)2Ph (5)
The thermal ellipsoids representation for compounds 3 and 5 are depicted in Figures 1
and 2, respectively.
Figure 1. Thermal ellipsoids representation at 30% probability and atom numbering scheme
of 3. Only the carbon atoms with a major contribution (56%) are represented in the disordered
ethyl groups (C14 – C17). Hydrogen atoms were omitted for clarity.

Figure 2. Thermal ellipsoids representation at 30% probability and atom numbering scheme
of 5. Hydrogen atoms were omitted for clarity.
The two compounds have monomeric structures, with a distorted tetrahedral coordination
geometry about phosphorus, with bond angles ranging in 3/5 from 103.0(3)°/103.45(19)°
(C1‒P1‒C18) to 114.1(2)°/116.60(14)° (C18‒P1‒S1). The P=S interatomic distances in both
compounds are consistent with a double bond (1.947(3) Å in 3 and 1.9552(16) Å in 5, vs.
Ph2P(=S)–N=P(–SMe)Ph2: P=S 1.954(1), P–S 2.071(1) Ǻ [27], and of a similar magnitude with
the values observed in the related [2-(Me2NCH2)C6H4]3P=S or [2-(Me2NCH2)C6H4]2PhP=S [28].
3.2.2. Crystal and molecular structure of [CuCl{P(C6H4CH2NEt2-2)Ph2}] (7) and [CuCl{P
(C6H4CH2NEt2-2)2Ph}] (8)
The thermal ellipsoids representation for [7]2 and [8]2 are given in Figures 3 and 4,
respectively, while selected interatomic distances and angles are given in Table 2.
The copper(I) complexes 7 and 8 have dimeric structures, with a distorted tetrahedral
environment about each copper atom. In both compounds the triorganophosphane ligand behaves
as a bidentate chelating P,N moiety towards the metal centre.

Figure 3. Thermal ellipsoids representation at 30% probability and atom numbering scheme of
RN1,SN1’-[7]2. Hydrogen atoms were omitted for clarity.
Figure 4. Thermal ellipsoids representation at 30% probability and atom numbering scheme of
RN1,SN1’-[8]2. Only the carbon atoms with a major contribution (62%) are represented in the
disordered ethyl groups (C25 – C28). Hydrogen atoms were omitted for clarity.

Table 2. Selected interatomic distances (Å) and angles (o) in
[CuCl{P(C6H4CH2NEt2-2)Ph2}] (7) and [CuCl{P(C6H4CH2NEt2-2)2Ph}] (8)
7
8
Cu1−P1
2.1870(9)
2.3773(9)
2.193(2)
2.3593(9)
2.3593(9)
2.1998(14)
2.4224(12)
2.190(4)
Cu1−Cl1
Cu1···N1
Cu1···Cl1'
Cu1'···Cl1
2.3318(13)
2.3317(13)
P1‒Cu1‒N1
P1‒Cu1‒Cl1
N1‒Cu1‒Cl1
P1‒Cu1‒Cl1'
N1‒Cu1‒Cl1'
Cl1‒Cu1‒Cl1'
Cu1‒Cl1‒Cu1'
99.87(7)
117.34(3)
108.67(6)
124.20(3)
106.99(7)
99.04(3)
100.00(11)
109.53(5)
107.26(10)
130.41(5)
108.97(11)
99.30(4)
80.96(3)
80.70(4)
The dimeric association is realized in both compounds by bridging chlorine atoms
(Cu1···Cl1' 2.3593(9) Å in 7 and 2.3317(13) Å in 8, vs. ΣrvdW(Cu,Cl) 3.20 Å [29,30]). The
dimeric structure observed for compound 7 resembles that one previously reported for the
copper(I) complexes [CuX{P(C6H4CH2NMe2-2)Ph2}] (X = Cl, I) [19]. In compound 8 the two 2-
(Et2NCH2)C6H4 groups attached to phosphorus behave in a different way: one of them is
intramolecularly coordinated to copper through a strong N→Cu interaction (2.19 Å vs.
ΣrvdW(Cu,N) 2.94 Å [29,30]), while the other one remains dangling, with the N2/N2' atoms
pushed far away from the coordination sphere of phosphorus or copper. This behaviour of the
P(C6H4CH2NEt2-2)2Ph ligand is different from that one observed in the copper(I) complex
[CuCl{P(C6H4CH2NMe2-2)2Ph}] where both nitrogen atoms are intramolecularly coordinated,
one of them to copper and the other one to phosphorus. Such a behaviour preserve the distorted
tetrahedral coordination geometry about phosphorus with bond angles ranging in 7/8 from
102.73(13)° (C7‒P1‒C18)/101.33(15)° (C7‒P1‒Cu1) to 118.13(10)°/ 124.10(14)°
(C18‒P1‒Cu1). The N→Cu interactions in compounds 7 and 8 are close to the values previously

observed in the copper complexes with the related methyl substituted ligands,
[CuX{P(C6H4CH2NMe2-2)2Ph}] or [CuX{P(C6H4CH2NMe2-2)Ph2}] (X = Cl, I) [19]. The
intramolecular N→Cu interaction results in two six membered CuPC3N rings in each dimer,
which are not planar, but folded about the imaginary axes P1···C7 and P1'···C7' in 7 and P1···C13
and P1'···C13' in 8, respectively, with twisted boat conformations. The intramolecular N→Cu
coordination induces planar chirality [31] and the compounds crystallize as mixtures of R and S
isomers which are interconnected in RN1,SN1’ and SN1,RN1’ dimers in both compounds.
Alternatively, by applying the skew line convention [31], the structure of the copper compounds
might be discussed in terms of λ and δ isomers. Therefore, compounds 7 and 8 crystalize as a
racemate of λCu1/δCu1' and δCu1/λCu1' dimers, where δ and λ refer to the chirality of the six-
membered chelate rings associated with copper.
The two dimeric structures are tricyclic systems with planar Cu2Cl2 cores and the ligands
displayed trans each other with respect to the relative positions of the nitrogen and the
phosphorus atoms towards the planar Cu2Cl2 central unit.
Conclusions
The liquid phosphanes P(C6H4CH2NEt2-2)Ph2 (1) and P(C6H4CH2NEt2-2)2Ph (2) were
used in oxidation reactions with elemental chalcogens (sulfur and selenium), as well as in
complexation reactions with CuCl. The 1H NMR spectra of the reported species brought no clear
evidences for a C,N coordination pattern of the 2-Et2NCH2C6H4 group in solution. For the
species bearing two aryl groups 2-Et2NCH2C6H4, each of them with a pendant arm capable for
1
intramolecular coordination, the H and the 13C NMR spectra suggest their equivalence in
solution. For the copper complex 8 the solid state structure determined by single crystal X ray
diffraction revealed a different behaviour of the two 2-Et2NCH2C6H4 groups, one of them
behaving as a C,N chelating moiety towards copper, while the pendant arm of the other is pushed
far away from the coordination sphere of the metal or the phosphorus atom.
Acknowledgements
The financial support from National University Research Council of Romania (Research
Project PNII-ID-PCE-2011-3-0659) is greatly acknowledged.

Supplementary material
CCDC 1557271 for 3, 1557270 for 5, 1558371 for 7 and 1558370 for 8 contain the
supplementary crystallographic data for this contribution. These data can be obtained free of
charge from the Cambridge Crystallographic Data Centre via
www.ccdc.cam.ac.uk/data_request/cif
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Graphical abstract
The triarylphosphanes P(C6H4CH2NEt2-2)nPh3-n (n = 1, 2) behave as P,N-chelating ligands in their
copper(I) complexes [CuCl{P(C6H4CH2NEt2-2)nPh3-n}]. Both copper derivatives have dimeric solid
state structures with bridging chlorine atoms. The oxidation with elemental S or Se resulted in
the P(V) species EP(C6H4CH2NEt2-2)nPh3-n (E = S, Se).

Highlights
•
Triorganophosphanes with aryl groups with pendant arms, of type P(C6H4CH2NEt2-2)nPh3-n (n = 1,
2)
•
•
•
•
Dimeric copper(I) complexes of type [CuCl{P(C6H4CH2NEt2-2)nPh3-n}]2
P,N-chelating behaviour towards Cu(I) in both complexes
Planar chirality determined by the intramolecular NꢀCu coordinaꢁon
Oxidation with S or Se resulted in triarylphosphane chalcogenides