Synthesis, spectroscopy, electrochemistry, and coordination chemistry of substituted phosphine sulfides and selenides

Article abstract of DOI:10.1016/j.poly.2015.07.008

Phosphines and phosphine chalcogenides are important ligands for various metal systems, especially catalysts. Based on previously synthesized phosphine oxide ligands, we describe here the synthesis and characterization of a series of compounds having the general formula, EPPh₂Ar, E = S, Se; Ar = 1-naphthyl, 9-phenanthryl, 9-anthracenyl, 1-pyrenyl. Reaction of EPPh₂(9-phenanthryl), E = S, Se, with HAuCl₄ yields ArPh₂PEAuCl. Similar to the phosphine oxide derivative, the anthracenyl compounds, EPPh₂(9-anthracenyl), showed a nonplanar conformation within the anthracene ring as observed using X-ray crystallography. The difference in fluorescence spectrum relative to the parent aryl species is attributed to this deformation. The deviation is probably due to steric strain within the phosphine ligand due to its position on the anthracenyl ring since DFT calculations suggest that the 1-anthracenyl ligand should be planar. Each compound has been characterized using ¹H, ¹³C, ³¹P, and (where applicable) ⁷⁷Se NMR, and IR spectroscopy, with structure determination by X-ray crystallography. Finally, the electrochemistry of the unoxidized phosphines is reported, showing one-electron reductions in the polycyclic aromatic hydrocarbons.

Full text of DOI:10.1016/j.poly.2015.07.008

Accepted Manuscript
Synthesis, spectroscopy, electrochemistry, and coordination chemistry of sub-
stituted phosphine sulfides and selenides
Andrew T. Breshears, Andrew C. Behrle, Charles L. Barnes, Charles H. Laber,
Gary A. Baker, Justin R. Walensky
PII:
S0277-5387(15)00363-0
DOI:
http://dx.doi.org/10.1016/j.poly.2015.07.008
POLY 11394
Reference:
Polyhedron
To appear in:
Received Date:
Accepted Date:
9 May 2015
7 July 2015
Please cite this article as: A.T. Breshears, A.C. Behrle, C.L. Barnes, C.H. Laber, G.A. Baker, J.R. Walensky,
Synthesis, spectroscopy, electrochemistry, and coordination chemistry of substituted phosphine sulfides and
selenides, Polyhedron (2015), doi: http://dx.doi.org/10.1016/j.poly.2015.07.008
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers
we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and
review of the resulting proof before it is published in its final form. Please note that during the production process
errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Synthesis, Spectroscopy, Electrochemistry, and Coordination Chemistry of Substituted
Phosphine Sulfides and Selenides
Andrew T. Breshears, Andrew C. Behrle, Charles L. Barnes, Charles H. Laber, Gary A. Baker,
and Justin R. Walensky*
Department of Chemistry, University of Missouri, Columbia, MO 65211, USA
walenskyj@missouri.edu
Phone: (573) 882-0608
Abstract
Phosphines and phosphine chalcogenides are important ligands for various metal systems,
especially catalysts. Based on previously synthesized phosphine oxide ligands, we describe here
the synthesis and characterization of a series of compounds having the general formula,
EPPh2Ar, E = S, Se; Ar = 1-naphthyl, 9-phenanthryl, 9-anthracenyl, 1-pyrenyl. Reaction of
EPPh2(9-phenanthryl), E = S, Se, with HAuCl4 yields ArPh2PEAuCl. Similar to the phosphine
oxide derivative, the anthracenyl compounds, EPPh2(9-anthracenyl), showed a nonplanar
conformation within the anthracene ring as observed using X-ray crystallography. The difference
in fluorescence spectrum relative to the parent aryl species is attributed to this deformation. The
deviation is probably due to steric strain within the phosphine ligand due to its position on the
anthracenyl ring since DFT calculations suggest that the 1-anthracenyl ligand should be planar.
1
31
Each compound has been characterized using H, 13C, P, and (where applicable) 77Se NMR,
and IR spectroscopy, with structure determination by X-ray crystallography. Finally, the
electrochemistry of the unoxidized phosphines is reported, showing one-electron reductions in
the polycyclic aromatic hydrocarbons.
1

Introduction
Phosphines are commonly employed as coordinating ligands to metal centers for varying
their steric and electronic properties.1,2 Changing these parameters can exert a significant effect
over the catalytic and redox chemistry of metal complexes. The use of phosphines has been
indispensable for the first generations of the Grubbs,3 Wilkinson,4 and Heck catalysts.5-9 In
recent years, various groups have investigated how changing substituents and steric bulk around
phosphorus changes the ligand chemistry. These investigations have included heteroatomic
polycyclic aromatic substituents,10 increased steric properties of phenyl groups,11-13 and
oxidation chemistry.14,15 In addition, sulfur and selenium-based ligands have become
increasingly studied due to their relevance in medicine and biological systems.16,17
Previous work involving EPPh2Ar (E = S, Se; Ar = polycyclic aromatic hydrocarbon) ligands
is limited (Figure 1) and there are no examples for Ar = phenanthryl or pyrenyl. Recently, our
group examined the coordination chemistry of phosphine oxide ligands of the form OPPh2Ar (Ar
= naphthyl, phenanthryl, anthracenyl, or pyrenyl) with uranyl nitrate, UO2(NO3)2.18 One feature
of these ligands is an unusual red-shift in the fluorescence spectrum for the anthracenyl-
derivative. To probe this further, we examine the sulfur and selenium analogs of those phosphine
ligands and their coordination chemistry with Au(I) as well as their electrochemical and
spectroscopic properties.
2

Figure 1. Examples of known triarylphosphine chalcogenide compounds. Numerals identify the
19-25
literature references reporting the corresponding species.
Experimental
General considerations. All materials were purchased (Sigma-Aldrich, St. Louis, MO) at 95%
purity or higher and used as received. Reactions were conducted in a Vacuum Atmosphere, Inc.
nitrogen atmosphere dry box or using Schlenk line techniques. Gold(I) compounds were handled
with exclusion of light unless otherwise specified. HAuCl4 (Strem) was used as received.
Phosphines were synthesized according to their literature procedures.18,26,27 All solvents used
were purchased anhydrous, stored over activated 4 Å molecular sieves, and sparged with
1
nitrogen prior to use. Benzene-d6 (Cambridge Isotope Laboratories) was used as received. H,
31
13C, and P NMR spectroscopy were obtained using a 250 MHz ARX, 300 MHz DRX, or 500
MHz DRX Bruker spectrometer. 1H NMR spectrum resonances were referenced internally to the
3

residual protio impurities at δ 5.32 ppm (CDHCl2) or at δ 7.16 ppm (C6D5H). 13C NMR spectrum
resonances were referenced internally to the deuterated solvent peaks at δ 53.52 ppm (CD2Cl2) or
δ 128.00 ppm (C6D6). 31P NMR spectra were referenced externally to 0.00 ppm with 85% H3PO4
in D2O. 77Se NMR spectra were externally referenced to 460.00 ppm with 1.0 M diphenyl
diselenide in C6D6. Infrared spectra were recorded using KBr pellets on a Perkin-Elmer
Spectrum One FT-IR spectrometer. Elemental analyses were performed by Atlantic Microlab,
Inc. (Norcross, GA).
SPPh2(1-naphthyl), 1. A scintillation vial was charged with elemental sulfur (32 mg, 0.125
mmol) and a second scintillation vial was charged with PPh2(C10H7) (312 mg, 1.00 mmol).
Toluene (10 ml) and sulfur were added to the phosphine and stirred for 48 h. The solution was
then filtered over Celite and the solvent removed in vacuo to yield 1 as a white solid (338 mg,
98%). 1H NMR (C6D6, 500 MHz): δ 6.86 (dt, 1H, 3JH-H = 7.5 Hz, 4JP-H = 2.5 Hz, naph), 6.92-7.07
3
3
(m, 7H, naph and Ph), 7.14 (t, 1H, 3JH-H = 4.5 Hz, naph), 7.25 (dd, 1H, JP-H = 16.5, JH-H = 8.5
Hz, naph), 7.50 (d, 1H, 3JH-H = 8.5 Hz, naph), 7.56 (d, 1H, 3JH-H = 8.5 Hz, naph) 7.94 (ddd, 4H,
3
3JP-H = 13 Hz, JH-H = 7 Hz, 4JH-H = 1 Hz, Ph), 9.03 (d, 1H, 3JH-H = 8.5 Hz, naph). 13C{1H} NMR
(C6D6, 125 MHz): δ 124.11 (s, naph), 125.34 (naph), 126.33 (naph), 126.59 (naph), 127.81 (Ph),
2
128.00 (naph), 128.26 (d, JP-C = 14 Hz, naph), 128.48 (naph), 128.98 (naph), 131.08 (Ph),
2
1
1
132.52 (d, JP-C = 10 Hz, Ph), 133.62 (d, JP-C = 84 Hz , Ph), 134.33 (d, JP-C = 106 Hz, naph),
31
137.53 (naph). P{1H} NMR (C6D6, 101 MHz): δ 42.00. IR (KBr, cm-1): 3049 (m), 1591 (w),
1504 (m), 1478 (m), 1436 (s, C-P), 1390 (m), 1336 (m), 1313 (w), 1261 (w), 1179 (w), 1096 (s,
C=C), 1026 (m), 1000 (w), 979 (w), 827 (m), 800 (s), 776 (s, C=C-H), 710 (s, P-C), 691 (s,
P=S), 635 (s), 526 (s), 508 (s). Anal. Calc. for C22H17PS: C, 76.72%; H, 4.98%. Found: C,
76.82%; H, 5.26%.
4

SPPh2(9-phenanthryl), 2. A scintillation vial was charged with elemental sulfur (32 mg, 0.125
mmol) and a second scintillation vial was charged with PPh2(C14H9) (362 mg, 1.00 mmol). The
synthesis followed the same approach as that for 1, yielding 2 as a white solid (348 mg, 97%). 1H
NMR (C6D6, 500 MHz): δ 6.90-7.04 (m, 4H, phen and Ph), 7.08-7.19 (m, 4H, Ph), 7.22 (t, 1H,
4
3
3JH-H = 8 Hz, phen), 7.61 (d, 1H, JP-H = 17.5 Hz, phen), 8.00 (dd, 4H, JH-H = 8.5 Hz, 3JP-H = 7
Hz, Ph), 8.28 (d, 2H, 3JH-H = 8.5 Hz, phen), 8.34 (d, 2H, 3JH-H = 8.5 Hz, phen), 9.17 (d, 1H, 3JH-H
= 8.5 Hz, phen). 13C{1H} NMR (C6D6, 125 MHz): δ 122.91 (phen), 123.35 (phen), 126.5 (phen),
4
126.80 (phen), 127.1(Ph), 127.28 (phen), 128.70 (d, JP-C = 12.5 Hz, phen), 128.97 (phen),
129.12 (d, 4JP-C = 12.5 Hz, phen), 130.22 (d, 3JP-C = 15 Hz, Ph), 130.33 (d, 4JP-C = 22.5 Hz, phen),
4
4
2
131.43 (d, JP-C = 3 Hz, phen), 132.10 (phen), 132.34 (d, JP-C = 3 Hz, phen), 133.90 (d, JP-C
=
1
2
1
10 Hz, Ph), 133.8 (d, JP-C = 84 Hz, Ph), 135.92 (d, JP-C = 10 Hz, phen), 136.2 (d, JP-C = 110
Hz, phen). 31P{1H} NMR (C6D6, 101 MHz): δ 42.85. IR (KBr, cm-1): 2962 (m, =C-H), 1476 (w),
1448 (w), 1435 (s), 1385 (w), 1306 (w), 1261 (m), 1249 (w), 1158 (w), 1103 (s, C=C), 1023 (m),
952 (w), 903 (w), 859 (w), 803 (m), 773 (m), 750 (s), 716 (s, P-C), 691 (s, P=S), 652 (s), 599
(m), 558 (w), 518 (m). Anal. Calc. for C26H19PS: C, 79.16%; H, 4.85%. Found: C, 78.60%; H,
4.96%.
SPPh2(9-anthracenyl), 3. A scintillation vial was charged with elemental sulfur (32 mg, 0.125
mmol) and a second scintillation vial was charged with PPh2(C14H9) (362 mg, 1.00 mmol). The
reaction was then performed analogous to 1, yielding 3 as a white solid (339 mg, 94%). 1H NMR
3
(C6D6, 500 MHz): δ 6.77 (t, 2H, JH-H = 8 Hz, anth), 6.82-6.90 (m, 6H, Ph), 6.99 (t, 2 H, 7.5Hz,
anth), 7.66 (d, 2H, 3JH-H = 8.5, anth), 7.88-7.98 (m, 4H, Ph), 8.20 (s, 1H, anth), 8.37 (d, 2H, 3JH-H
13
2
= 9 Hz, anth). C{1H} NMR (C6D6, 125 MHz): δ 124.41 (d, JP-C = 87.5 Hz, anth), 125.39 (d,
3
3JP-C = 34 Hz, anth), 125.66 (d, JP-C = 34 Hz, anth), 126.67 (anth), 128.49 (anth), 129.20 (anth),
5

130.41 (d, 4JP-C = 2.5 Hz, anth), 131.24 (d, 2JP-C = 10 Hz, Ph), 131.80 (anth), 132.41 (Ph), 133.53
(d, 4JP-C = 4 Hz, anth), 133.75 (d, 4JP-C = 7.5 Hz, Ph) 133.88 (d, 4JP-C = 5 Hz, anth), 133.92 (d, 4JP-
C = 5 Hz, anth), 138.25 (d, 1JP-C = 107.5 Hz, Ph), 138.5 (d, 2JP-C = 81.25 Hz, anth). 31P{1H} NMR
(C6D6, 101 MHz): δ 34.37. IR (KBr, cm-1): 3056 (w), 2960 (m, =C-H), 1700 (w), 1685 (w), 1653
(w), 1617 (w), 1540 (w), 1481 (m), 1437 (s, C=C), 1384 (m), 1261 (w), 1093 (s, C=C-H, plane
bend), 1026 (m), 902 (m), 845 (w), 823 (m), 779 (m), 740 (s, P-C), 716 (m), 698 (s, P=S), 675
(w), 646 (w), 635 (w), 615 (w). Anal. Calc. for C26H19PS: C, 79.16%; H, 4.85%. Found: C,
79.14%; H, 5.16%.
SPPh2(1-pyrenyl), 4. A scintillation vial was charged with elemental sulfur (32 mg, 0.125
mmol) and a second scintillation vial was charged with PPh2(C16H9) (388 mg, 1.00 mmol). The
reaction was then performed analogous to 1, yielding 4 as a pale yellow solid (410 mg, 98%).
Low solubility and overlapping protons made assignment of proton and carbon resonances in
1
their respective NMR spectra unsuccessful. H NMR (C6D6, 500 MHz): δ 6.89-6.98 (m, 1H,
pyr), 7.0-7.08 (m, 6H, Ph), 7.54-7.8 (m, 4H, pyr), 7.84 (d, 1H, 3JH-H = 7.5 Hz, pyr), 7.91 (d, 1H,
3
3JH-H = 7.5 Hz, pyr), 8.00-8.07 (m, 4H, Ph), 9.28 (d, 1H, JH-H = 9 Hz, pyr). 13C{1H} NMR
3
3
(C6D6, 125 MHz,): δ 123.87 (d, JP-C = 12.5 Hz), 124.67, 125.24, 125.95 (d, JP-C = 12.5 Hz),
4
2
3
126.06, 127.41 (d, JP-C = 5 Hz), 128.67 (d, JP-C = 11.3 Hz), 129.27, 129.73, 130.70 (d, JP-C
=
1
4
1
12.5 Hz), 131.18 (d, JP-C = 106 Hz, Ph), 131.36 (d, JP-C = 2.5 Hz, CH), 131.37 (d, JP-C = 20
Hz), 132.96 (d, 2JP-C = 10 Hz, CH), 133.29 (d, 2JP-C = 9 Hz) 133.85 (d, 3JP-C = 7.5 Hz), 133.89 (d,
4
31
3JP-C = 7.5 Hz), 134.17, 134.24 (d, JP-C = 2.5 Hz), 134.84, 137.83. P{1H} NMR (C6D6, 101
MHz): δ 42.65. IR (KBr, cm-1): 3431 (wb), 3148 (w), 2961 (w), 1578 (w), 1435 (s), 1384 (s,
C=C-H), 1263 (w), 1207 (w), 1178 (w), 1098 (m), 1026 (w), 847 (w), 819 (w), 752 (m), 712 (s,
6

P-C), 692 (m, P=S), 659 (m), 514 (w), 493 (w). Anal. Calc. for C28H19PS: C, 80.36%; H, 4.58%.
Found: C, 80.34%; H, 4.71%.
SePPh2(1-naphthyl), 5. A scintillation vial was charged with elemental selenium (79 mg, 1.00
mmol). A second scintillation vial was charged with PPh2(C10H7) (312 mg, 1.00 mmol) then
dissolved in toluene and then transferred into the selenium scintillation vial and allowed to stir
for 48 h. The solution was then filtered over Celite and the solvent was removed in vacuo
1
3
yielding 5 as a white solid (377 mg, 96%). H NMR (C6D6, 500 MHz): δ 6.85 (dt, 1H, JH-H
=
7.5 Hz, 4JP-H = 2.5 Hz, naph), 6.92-7.03 (m, 7H, naph and Ph), 7.06 (t, 1H, 3JH-H = 3.0 Hz, naph),
7.22 (dd, 1H, 3JP-H = 16.5, 3JH-H = 7.0 Hz, naph), 7.49 (d, 1H, 3JH-H = 8.5 Hz, naph), 7.54 (d, 1H,
3
4
3JH-H = 8.5 Hz, naph) 7.97 (ddd, 4H, 3JP-H = 13.5 Hz, JH-H = 8.5 Hz, JH-H = 1.5 Hz, Ph), 9.04
(d, 1H, 3JH-H = 8.5 Hz, naph). 13C{1H} NMR (C6D6, 125 MHz): δ 124.22 (naph), 124.48 (d, 3JP-C
= 13.8 Hz, naph), 126.57 (naph), 126.72 (naph), 128.54 (d, 3JP-C = 9 Hz, Ph), 131.14 (d, 4JP-C = 3
Hz, Ph), 131.43 (d, 4JP-C = 3 Hz, naph), 131.86 (naph), 132.5 (d, 2JP-C = 10 Hz, Ph), 133.4 (d, 1JP-
2
1
= 88 Hz, Ph), 133.38 (d, JP-C = 10 Hz, naph) 134.7 (d, JP-C = 126 Hz, naph), 137.82 (naph),
C
31
1
139.08 (naph). P{1H} NMR (C6D6, 101 MHz): δ 31.85 (singlet with doublet satellites, JP-Se
=
77
1
748 Hz). Se{1H} NMR (C6 D6, 57 MHz): δ -252.71 (d, JP-Se = 748 Hz). IR (KBr, cm-1): 3050
(w), 2961 (w), 1591 (m), 1504 (m), 1477 (m), 1436 (s, C=C-H), 1390 (w), 1334 (w), 1312 (w),
1263 (m), 1181 (w), 1143 (w), 1095 (s, P-C), 1025 (m), 998 (m), 976 (w), 800 (s), 776 (s), 754
(m), 735 (m), 691 (s, P-C), 626 (m), 568 (s, P=Se), 529 (s), 504 (m). Anal. Calc. for C22H17PSe:
C, 67.53%; H, 4.38%. Found: C, 66.19%; H, 4.51%.
SePPh2(9-phenanthryl), 6. A scintillation vial was charged with PPh2(C14H9) (362 mg, 1.00
mmol) in toluene and elemental selenium (79 mg, 1.00 mmol) was added. The reaction was then
1
performed analogous to 5, yielding 6 as a white solid (398 mg, 98% yield). H NMR (C6D6, 500
7

MHz): δ 6.92-7.02 (m, 4H, phen and Ph), 7.08-7.15 (m, 4H, Ph), 7.22 (t, 1H, 3JH-H = 8 Hz, phen),
3
7.61 (d, 1H, 4JP-H = 17.5 Hz, phen), 8.00 (dd, 4H, JH-H = 8.5 Hz, 3JP-H = 7 Hz, Ph), 8.28 (d, 2H,
3
3
3JH-H = 8.5 Hz, phen), 8.34 (d, 2H, JH-H = 8.5 Hz, phen), 9.19 (d, 1H, JH-H = 8.5 Hz, phen).
13C{1H} NMR (C6D6, 125 MHz): δ 122.81 (phen), 123.25 (phen), 126.53 (phen), 126.74 (phen),
4
127.12 (Ph), 127.35 (phen), 128.71 (d, JP-C = 12.5 Hz, phen), 128.96 (phen), 130.05 (phen),
3
3
3
130.13 (d, JP-C = 7.5 Hz, phen), 130.33 (d, JP-C = 15 Hz, Ph), 130.43 (d, JP-C = 9 Hz, phen ),
131.46 (d, 4JP-C = 4 Hz, phen), 131.63 (d, 2JP-C = 9 Hz, Ph), 132.30 (d, 4JP-C = 3 Hz, phen), 132.33
(d, 1JP-C = 75, Ph), 133.51 (d, 2JP-C = 11 Hz, Ph), 135.55 (d, 2JP-C = 9 Hz, phen), 136.20 (d, 1JP-C
=
=
31
1
108 Hz, phen). P{1H} NMR (C6D6, 101 MHz): δ 32.84 (singlet with doublet satellites, JP-Se
1
748 Hz). 77Se{1H} NMR (C6 D6, 57 MHz): δ -258.80 (d, JP-Se = 748 Hz). IR (KBr, cm-1): 3025
(w), 2963 (m), 1478 (w), 1448 (w), 1435 (s, C=C), 1385 (w), 1308 (w), 1261 (w), 1247 (w),
1181 (w), 1158 (w), 1099 (s, P-C), 1092 (s), 1024 (m), 999 (w), 951 (w), 902 (w), 801 (w), 772
(s), 750 (s), 713 (m), 691 (s, P-C), 623 (m), 567 (s, P=Se), 537 (s), 515 (s). Anal. Calc. for
C26H19PSe: C, 70.75%; H, 4.34%. Found: C, 70.50%; H, 4.45%.
SePPh2(9-anthracenyl), 7. A scintillation vial was charged with elemental selenium (79 mg,
1.00 mmol) and a second scintillation vial was charged with PPh2(C14H9) (362 mg, 1.00 mmol).
The reaction was then performed analogous to 5, yielding 7 as a white solid (374 mg, 92%
1
yield). H NMR (C6D6, 500 MHz): δ 6.77 (t, 2H, 3JH-H = 8 Hz, anth), 6.80-6.87 (m, 6H, Ph), 7.13
3
(t, 2 H, 7.5 Hz, anth), 7.66 (d, 2H, JH-H = 8.5, anth), 7.92-8.01 (m, 4H, Ph), 8.16 (s, 1H, anth),
8.36 (d, 2H, 3JH-H = 9 Hz, anth). 13C NMR (C6D6, 125 MHz): δ 122.60 (d, 2JP-C = 78.5 Hz, anth),
3
3
125.33 (d, JP-C = 23.75 Hz, anth), 125.55 (d, JP-C = 9 Hz, anth), 126.66 (s, anth), 128.49 (s,
4
2
anth), 129.27 (s, anth), 130.41 (d, JP-C = 2.5 Hz, anth), 131.24 (d, JP-C = 10 Hz, Ph), 131.30 (s,
anth), 132.41 (s, Ph), 133.53 (d, 4JP-C = 4 Hz, anth), 133.75 (d, 4JP-C = 7.5 Hz, Ph), 133.48 (d, 4JP-
8

C = 5 Hz, anth), 133.54 (d, 4JP-C = 6.25 Hz, anth), 136.25 (d, 1JP-C = 107.5 Hz, Ph), 136.71 (d, 2JP-
31
1
= 72.5 Hz, anth). P NMR (C6D6, 101 MHz): δ 25.56 (singlet with doublet satellites, JP=Se
=
C
1
752 Hz). 77Se{1H} NMR (C6 D6, 57 MHz): δ -290.25 (d, JP=Se = 752 Hz). IR (KBr, cm-1): 3049
(w), 2956 (m), 2927 (m), 1616 (w), 1512 (w), 1480 (m), 1437 (s, C=C), 1384 (m), 1308 (w),
1262 (w), 1248 (w), 1178 (w), 1154 (w), 1092 (s), 1024 (m), 999 (w), 957 (w), 900 (m), 843 (w),
822 (m), 778 (m), 739 (s), 695 (s), 558 (m), 522 (s, P=Se), 515 (s). Anal. Calc. for C26H19PSe: C,
70.75%; H, 4.34%. Found: C, 71.17; H, 4.55%.
SePPh2(1-pyrenyl), 8. A scintillation vial was charged with elemental selenium (79 mg, 1.00
mmol) and a second scintillation vial was charged with PPh2(C16H9) (388 mg, 1.00 mmol). The
reaction was then performed analogous to 5, yielding 8 as a green solid (402 mg, 96%). As with
SPh2Pyrenyl, low solubility and an overlapping proton spectrum made assignment of proton and
1
carbon resonances in their respective NMR spectra unsuccessful. H NMR (C6D6, 500 MHz): δ
6.77 (t, 1H, 3JH-H = 8 Hz, pyr), 6.89-7.08(m, 6H, Ph), 7.50-7.89 (m, 5H, pyr), 7.80 (d, 1H, 3JH-H
=
7.5 Hz, pyr), 7.93 (d, 1H, 3JH-H = 7.5 Hz, pyr), 8.04-8.11 (m, 4H, Ph), 9.29 (d, 1H, 3JH-H = 10 Hz,
13
pyr). C{1H} NMR (C6D6, 125 MHz): δ 123.97 (d, JP-C = 13.8 Hz), 124.67, 125.24, 125.95 (d,
3JP-C = 12.5 Hz), 126.06, 127.49 (d, 4JP-C = 5 Hz), 128.67 (d, 2JP-C = 11.3 Hz, Ph), 129.28, 129.71,
5
1
5
130.46 (d, JP-C = 2.5 Hz), 131.20 (d, JP-C = 106 Hz, Ph), 131.41 (d, JP-C = 2.5 Hz), 131.81 (d,
3
4
3
2JP-C = 11.3 Hz), 132.96 (d, JP-C = 10 Hz), 133.28 (d, JP-C = 4 Hz), 133.5 (d, JP-C = 10 Hz),
3
133.55 (d, JP-C = 10 Hz), 134.17, 136.46, 137.04, 137.83. 31P{1H} NMR (C6D6, 101 MHz): δ
32.34 (singlet with doublet satellites, 1JP-Se = 746 Hz). 77Se{1H} NMR (C6D6; 57 MHz): δ -336.4
1
(d, JSe-P = 746 Hz). IR (KBr, cm-1): 3046 (m), 2959 (m), 2926 (m), 2855 (w), 1577 (w), 1477
(w), 1457 (w), 1436 (S, C=C), 1384 (m), 1261 (m), 1208 (w), 1180 (w), 1099 (s), 1025 (m), 998
9

(w), 843 (s), 819 (m), 749 (m), 691 (s), 639 (w), 601 (m), 555 (s, P=Se), 514 (m). Anal. Calc. for
C28H19PSe: C, 72.26%; H, 4.12%. Found: C, 71.91%; H, 4.51%.
[(9-phenanthryl)Ph2PS]AuCl, 9. A scintillation vial was charged with 0.25 M HAuCl4 (1.96
mL, 0.49 mmol) in air. A second scintillation vial was charged with 2 (396 mg, 1.00 mmol) and
brought out of the glove box. The two were then added quickly to a Schlenk flask with a high
flow rate of N2 and dissolved in anhydrous ethanol that had been dried over 4 Å molecular
sieves. The reaction was stirred overnight to yield a brown solution. The reaction mixture was
filtered over a medium-porosity ceramic frit. The white precipitate was washed with cold ethanol
(2 × 5 ml) and extracted with methylene chloride (10 ml) and concentrated to yield 9 as colorless
crystals (229 mg, 40%). 1H NMR (C6D6, 300 MHz): δ 6.83-7.03 (m, 6H, Ph), 7.29-8.00 (m, 10H,
Ph (4H) and phen (6H)), 8.31 (dd, 2H, 3JH-H = 5.5 Hz, 3JH-H = 4.5 Hz, phen), 8.70 (d, 1H, 3JH-H
=
13
4.5 Hz, phen). C{1H} NMR (C6D6, 75 MHz): δ 122.98 (phen), 123.56 (phen), 127.15 (phen),
4
127.32 (phen), 127.40 (Ph), 128.28 (phen), 128.70 (d, JP-C = 12.5 Hz, phen), 129.12 (phen),
129.37 (d, 4JP-C = 12.5 Hz, phen), 130.22 (d, 3JP-C = 15 Hz, Ph), 130.59 (d, 4JP-C = 22.5 Hz, phen),
131.03(d, 4JP-C = 3 Hz, phen), 131.81 (s, phen), 132.32 (d, 4JP-C = 3 Hz, phen), 132.52 (d, 2JP-C
=
10 Hz, Ph), 135.02 (d, 1JP-C = 84 Hz, Ph), 135.12 (d, 2JP-C = 10 Hz, phen), 136.60 (d, 1JP-C = 110
Hz, phen). 31P{1H} NMR (C6D6, 101 MHz): δ 27.1. IR (KBr, cm-1) 3058 (m), 1527 (w), 1436 (s),
1384 (s), 1249 (m), 1185 (w), 1095 (s), 1051 (w), 998 (m), 953 (m), 899 (w), 742 (s), 716 (m),
686 (m), 622 (m), 586 (m), 556 (m), 512 (s, P-S), 482 (w). Anal. Calc. for C26H19PSAuCl: C,
45.71%; H, 3.14%. Found: C, 45.70%; H, 3.22%.
[(9-phenanthryl)Ph2PSe]AuCl, 10. A scintillation vial was charged with 0.25 M HAuCl4 (1.96
ml, 0.49 mmol) and a second scintillation vial was charged with 6 (444 mg, 1.00 mmol) then
brought out of the glove box. The reaction and isolation of product were carried out in the same
10

manner as 9, resulting in the isolation of 10. The solvent was evaporated slowly to form colorless
crystals (228 mg, 35%). Crystals suitable for X-ray crystallographic analysis were obtained from
1
slow evaporation of 1:1 benzene and dichloromethane solution at room temperature. H NMR
(C6D6, 300 MHz): δ 7.49 (t, 1H, 3JH-H = 7.8 Hz, phen), 7.60-7.69 (m, 6H, Ph), 7.71-7.95 (m, 9H,
phen and Ph), 8.64 (d, 1H, 3JH-H = 8.4 Hz, phen), 8.87 (d, 1H, 3JH-H = 8.4 Hz, phen), 8.94 (d, 1H,
3JH-H = 8.4 Hz, phen).13C{1H} NMR (C6D6, 75 MHz): δ 122.82 (phen), 123.26 (phen), 123.60
4
(phen), 124.06 (phen), 126.81 (Ph), 127.28 (phen), 127.58 (d, JP-C = 12.5 Hz, phen), 127.88
(phen), 128.20 (phen), 128.44 (d, 3JP-C = 7.5 Hz, phen), 129.48 (d, 3JP-C = 15 Hz, Ph), 129.54 (d,
1JP-C = 114 Hz, phen), 130.30 (d, 4JP-C = 4 Hz, phen), 130.40 (d, 2JP-C = 9 Hz, Ph), 130.00 (d, 4JP-
C = 3 Hz, phen), 132.02 (d, 1JP-C = 75 Hz, Ph), 132.42 (d, 2JP-C = 11 Hz, Ph), 135.00 (d, 2JP-C = 9
1
31
Hz, phen), 136.82 (d, JP-C = 108 Hz, phen). P{1H} NMR (C6D6, 101 MHz): δ 27.75 (singlet
1
77
1
with doublet satellites, JP-Se = 410 Hz). Se{1H} NMR (C6D6, 57 MHz): 104.5 (d, JSe-P = 410
Hz). IR (KBr, cm-1): 2962 (m), 2925 (m), 2855 (w), 1481 (w), 1434 (m), 1384 (s), 1262 (m),
1100 (m), 1025 (m), 803 (m), 749 (m), 693 (w), 611 (w), 566 (w), 507 (w). Anal. Calc. for
C22H19PSeAuCl: C, 46.35%; H, 2.84%. Found: C, 46.12%; H, 2.64%.
Reaction of 9 and 10 with tetrahydrothiophene(tht). Complexes 9 (313 mg, 0.5 mmol) and
10 (336 mg, 0.5 mmol) were treated with tetrahydrothiophene (tht), (44 mg, 0.5 mmol), and
stirred in benzene overnight. The solvent was removed in vacuo and the product recrystallized
1
for which the unit cell dimensions matched those of (tht)AuCl. The H and 31P{1H} NMR
spectra afforded resonances consistent with that of 2, 6, and (tht)AuCl.
Electrochemistry. Cyclic voltammetry (CV) experiments were conducted using a CH
Instruments (CHI) model 700D series workstation and the data were analyzed using CHI
software version 12.05. All experiments were conducted inside a N2 atmosphere glovebox with
11

an electrochemical cell consisting of a 10 mL vial, glassy carbon electrode (3-mm diameter), a
platinum wire counter electrode, and a silver wire plated with AgCl as a quasi-reference
electrode. The working electrode surfaces were polished prior to each set of experiments and
were periodically replaced to prevent buildup of oxidized or reduced products on the electrode
surfaces. Solutions employed during CV studies ranged from 1.0 to 1.5 mM in analyte
concentration and contained 100 mM [nBu4N][PF6] as supporting electrolyte. Potentials were
reported versus Fc/Fc+, which was added as an internal standard for calibration at the end of each
experiment. All data were collected in a positive-feedback iR compensation mode to minimize
uncompensated resistance in the solution cells. The THF solution cell resistances were measured
prior to each run to ensure resistances were approximately 1500 Ω or less.
Single crystal X-ray diffraction experiments. The selected single crystal was mounted on a
nylon cryoloop using viscous hydrocarbon oil. X-ray data collection was performed at 173(2) K.
The X-ray data were collected on a Bruker CCD diffractometer with monochromated Mo-Kα
radiation (λ = 0.71073 Å). The data collection and processing utilized Bruker Apex2 suite of
programs.28 The structures were solved using direct methods and refined by full-matrix least-
squares methods on F2 using Bruker SHELX-97 program.29 All non-hydrogen atoms were
refined with anisotropic displacement parameters. All hydrogen atoms were placed at calculated
positions and included in the refinement using a riding model. Thermal ellipsoid plots were
prepared by using X-seed30 with 50% of probability displacements for non-hydrogen atoms. The
crystal parameters for 1-8 are highlighted in Table 1, and 9-10 are highlighted in Table 2.
Table 1. X-ray crystallographic data for complexes 1-8.
1
2
3
4
5
6
7
8
CCDC Deposit Number
Empirical Formula
1057597
1057598
C26H19PS
1057596
C26H19PS
1057599
C28H19PS
1057594
1057593
C26H19PSe
1057592
C26H19PSe•
1057595
C28H19PSe
C22H17PS•0.5(
C22H17PSe•0.5(
12

C7H8)
C7H8)
0.5(C7H8)
467.88
Formula weight (g/mol)
Crystal Habit, color
389.95
394.44
394.44
418.46
437.35
441.34
465.36
Plate, Colorless
Plate, Colorless
Plate, Colorless
Prism,
Plate,
Prism,
Block,
Plate,
Colorless
Colorless
Colorless
Colorless
Colorless
Temperature (K)
Space group
Crystal system
Volume (Å3)
a (Å)
173(2)
C2/c
173(2)
P21/n
173(2)
P-1
173(2)
P-1
173(2)
P21/c
173(2)
P21/n
173(2)
P-1
173(2)
P-1
Monoclinic C
4100.2(15)
11.570(2)
14.878(3)
24.459(5)
90.0
Monoclinic P
1993.2(3)
13.4383(12)
9.2261(9)
16.0765(15)
90.0
Triclinic P
1995.0(13)
10.234(4)
12.379(4)
17.407(6)
101.530(5)
91.073(5)
111.838(3)
4
Triclinic P
1057.82(19)
9.200(11)
10.553(13)
12.337(15)
66.615(16)
74.640(17)
80.613(18)
2
Monoclinic P
4165.1 (13)
11.555(2)
15.173(3)
24.382 (4)
90.0
Monoclinic P
1998.10(10)
13.5233(4)
9.1692(3)
16.1177(4)
90.0
Triclinic P
2159.5(19)
12.566(6)
12.864(6)
16.340(8)
92.376(7)
112.045(6)
114.796(6)
4
Triclinic P
1056.28(3)
9.2015(2)
10.6136(2)
12.4204(2)
65.547(1)
73.595(1)
79.512(1)
2
b (Å)
c (Å)
α (˚)
β (˚)
103.143(2)
90.0
90.423(1)
90.0
103.010(2)
90.0
91.224(1)
90.0
γ (˚)
Z
8
4
8
4
1.263
1.314
1.314
1.314
1.395
1.467
1.439
1.463
Calculated
(Mg/m3)
density
0.24
0.25
0.25
0.24
1.89
3.35
1.83
3.2
Absorption coefficient
(mm-1)
R1 = 0.035
R1 = 0.043
R1 = 0.039
R1 = 0.053
R1 = 0.045
R 1= 0.032
R1 = 0.068
R1 = 0.024
Final
R indices [I >
2σ(I)]
wR2 = 0.100
wR2 = 0.100
wR2 = 0.091
wR2 = 0.136
wR2 = 0.176
wR2 = 0.089
wR2 = 0.193
wR2 = 0.063
Table 2. X-ray crystallographic data for complexes 9 and 10.
9
10
CCDC Deposit Number
Empirical Formula
Formula weight (g/mol)
Crystal Habit, color
Temperature (K)
1057591
1057590
C26H19AuClPS
626.86
C26H19AuClPSe•C6H6
751.87
Prism, Colorless
173(2)
Prim, colorless
173(2)
Space group
Monoclinic
Triclinic
13

Crystal system
P21/c
4422.8
P-1
1381.5
Volume (Å3)
a (Å)
16.0492(15)
18.1088(16)
15.7268(15)
90
9.788(2)
12.054(3)
12.466(3)
79.177(2)
75.285(2)
79.037(2)
2
b (Å)
c (Å)
α (˚)
β (˚)
104.618(1)
90
γ (˚)
Z
8
Calculated density (Mg/m3)
Absorption coefficient (mm-1)
Final R indices [I > 2σ(I)]
1.883
1.807
6.95
6.82
R1 = 0.032
wR2 = 0.063
R1 = 0.035
wR2 = 0.080
Computational details. The electronic structures of complexes 1-8 and their unoxidized
structures were examined using the Gaussian09 suite of software31 at the B3LYP32 (Becke-333
exchange and Lee-Yang-Parr34 correlation functional) level of theory.
Full geometry
optimizations were performed and stationary points were determined to be global minima using
analytical frequency calculations. The Pople double-ζ quality basis set, 6-31G(d,p),35,36 was used
for all atoms. NCIS(1) values were calculated as described previously,10 using Gaussview to
place the ghost atom 1 Å above or below the centroid of the ring.
Results and Discussion
Synthesis. The phosphine ligands, PPh2Ar, Ar = C10H7 (1-naphthyl), C14H9 (9-phenanthryl),
C14H9 (9-anthracenyl), and C16H9 (1-pyrenyl), were synthesized as previously reported18,26,27 and
oxidized with either an eighth of an equivalent of elemental sulfur or one equivalent of selenium
14

to produce the corresponding E=PPh2Ar complexes, eq 1, E = S, Se. Coordination of EPPh2(9-
phenanthryl) to Au(I) was achieved by reaction of two equivalents of EPPh2Ar with HAuCl4 to
yield (Ph2ArPE)AuCl, E = S, 9; Se, 10. No attempt to determine the byproducts of the reactions
with auric acid was pursued but similar reactivity has been reported previously. 37
Ar
Ar
E
1/8 S8; Se
P
P
(1)
Toluene, RT
48 h
E = S; Ar = 1-naphthyl, 1
E = S; Ar = 9-phenanthryl, 2
E = S; Ar = 9-anthracenyl, 3
E = S; Ar = 1-pyrenyl, 4
E = Se; Ar = 1-naphthyl, 5
E = Se; Ar = 9-phenanthryl, 6
E = Se; Ar = 9-anthracenyl, 7
E = Se; Ar = 1-pyrenyl, 8
Spectroscopy. Each reaction was monitored by 31P NMR spectroscopy. Upon oxidation, a
general shift downfield of the resonance from the unoxidized product was observed, Table 3. The
difference between 2 and Au complex, 9, was ~15 ppm, while 6 and Au complex, 10, differed by
5 ppm. Interestingly, there is no correlation between the 31P NMR chemical shifts and the size of
the aryl ring. However, for S=PPh2Ar, 3, Se=PPh2Ar, 7, Ar = 9-anthracenyl, the 31P NMR
resonances are shifted upfield at 34.4 and 25.6 ppm, respectively, when compared to the
unoxidized phosphine. This deviation of complexes 3 and 7 could be due to loss of planarity
(described later), which then creates an upfield shift in the 31P NMR spectra due to relatively
greater σ- than π-bonding between phosphorus and the aryl ipso carbon. Different electronic
factors on the phosphine have been known to influence the 31P NMR spectrum.38 However, a
strong correlation between the aromatic substituent on the phosphine and the shift of the 77Se
15

NMR resonance, Table 4, was observed for compounds 5-8: increasing the electron withdrawing
ability of the polycyclic aromatic hydrocarbon leads to an upfield shift of the 77Se NMR
resonance.
Table 3. 31P NMR chemical shifts for 1-10.
Compound
31P NMR Chemical Shift (ppm)
42.0
42.8
34.4
42.7
31.8
32.8
25.6
32.3
27.1
27.8
1
2
3
4
5
6
7
8
9
10
16

Table 4: 77Se NMR spectroscopy resonances for Se containing compounds, 5-8 and 10.
Compound
77Se NMR chemical resonance (ppm)
77Se – 31P coupling (Hz)
–252.71
–258.80
–290.25
–336.40
104.50
748
748
752
746
410
5
6
7
8
10
Both 5 and 6 show 77Se resonances very close to that of triphenylphosphine selenide (–262
ppm)39 while those for 7 and 8 are significantly upfield from 5 and 6. Finally, as to be expected,
77Se NMR spectroscopy of 10 shows a large shift downfield with a significant decrease in Se–P
coupling which denotes the weakening of the Se-P bond from selenium donating electron density
to gold.
Each reaction was monitored by IR spectroscopy for the P-Se or the P-S stretching
frequencies, Table 5. The same trends for the NMR spectroscopy also apply to those observed in
the IR spectroscopy: 1) There is no correlation between ring size and P-E (E = S, Se) stretching
frequency and 2) the frequency appears at a lower wave number when coordinated to Au(I).
17

Table 5. IR stretching frequency (cm-1) complexes 1-10.
Bond stretching
1, E = S 2, E = S 3, E = S 4, E = S 5, E = Se
6, E = Se
7, E = Se
8, E = Se
9, E = S 10, E= Se
frequency (cm-1)
v(P=E)asym
691
691
698
692
568
569
522
555
512
Not
observed
Optical Spectroscopy. The electronic absorbance spectra for the phosphine sulfides and
selenides dissolved in toluene are provided in Figure 2 and accord well with the absorbance
profiles expected for the parent aryl phosphine compounds.18 The corresponding fluorescence
emission spectra are shown alongside. As we observed earlier for the corresponding phosphine
oxides, the order of the emission intensities for the phosphine sulfides (selenides) is 4(8) > 3(7)
>> 2(6) >> 1(5).
As shown in Figure 2A, the absorbance profiles for the naphthyl phosphine complexes 1 and
5 show a relatively narrow absorbance in the 275 nm to 360 nm range, with a maximum
absorbance near 290 nm. The phenanthryl species 2 and 6 display absorption maxima at 281 nm,
however, 6 shows a broader spectrum relative to its sulfur counterpart, with a “tail” extending
from 320 to 375 nm (Figure 2B). The pyrenyl phosphine sulfide (4) and selenide (8) results,
shown in Figure 2C, display the typical vibrational features expected for unsubstituted pyrene
monomer. The fact that well-defined vibrational peaks (i.e., peaks I, II, IV, and V) can still be
observed for the pyrene substituted at the 1-position is unusual.40,41 Indeed, the analogous
pyrenyl phosphine oxide studied previously18 showed an emission profile more typical of 1-
substituted pyrenyl compounds (i.e., two well-resolved monomeric bands near 375 nm and 400
nm). We note that the relative fluorescence intensity of the sulfide analog (4) was twice that of
the selenide analog (8), for an identical absorbance at the excitation wavelength (325 nm). This
is a general trend observed for all of the aryl phosphines studied here.
18

When excited at 310 nm, complexes 3 and 7 show vibronic emission similar to that of
conventional anthracene monomer, displaying peaks near 380, 402, 430, and 450 nm, Figure 3.
When the excitation wavelength was red shifted to 410 nm, the emission observed from the
anthracenyl phosphine sulfide and selenide ligands became structureless and was red-shifted by
some 50 nm relative to typical anthracene monomer emission, a result mirroring that seen with
the anthracenyl phosphine oxide earlier.18,42
19

Figure 2. Normalized absorbance (broken profiles) and fluorescence emission (solid curves)
spectra of (A) 1 and 5, (B), 2 and 6, and (C) 4 and 8. The vertical bars within each panel indicate
the excitation wavelengths employed to generate the emission spectra shown.
20

Figure 3. Normalized absorbance spectra (broken profiles) and fluorescence emission spectra
(solid profiles) of the anthracenyl phosphine complexes 3 (red, S) and 7 (green, Se) measured in
toluene. The emission spectra collected at different excitation wavelengths are offset vertically
for clarity. Proceeding from top to bottom, the excitation wavelength decreases in the order 410
nm, 350 nm, and 310 nm.
Electrochemistry of Phosphine Complexes. Electrochemical experiments were investigated for
phosphine compounds PPh2Ar: Ar = 1-naphthyl, 9-phenanthryl, 9-anthracenyl, and 1-pyrenyl, at
room temperature in THF. All the phosphine compounds displayed a one-electron irreversible
oxidation wave at positive potentials relative to Fc/Fc+ that can be attributed to the oxidation of
phosphine, Figure 4. Substitution of the various polycyclic aromatic hydrocarbon (PAH) groups
did not affect the oxidation potential of phosphine (see Supporting Information) and the
21

irreversible wave was independent of scan rates. These results are consistent with previously
published reports describing the electrochemical irreversible oxidation of PPh3.42,43
1.50
1.00
0.50
0.00
-0.50
-1.00
-1.50
-2.00
-2.50
-3.00
-3.50
Potential (V vs Fc/Fc+)
Figure 4. Representative cyclic voltammogram of PPh2Ar, Ar = 1-pyrenyl, displaying
irreversible one-electron oxidation wave at a positive potential with scan rate at 250 mVs–1.
Table 6 shows the redox potentials for the PPh2Ar (Ar = C10H7 (naphthyl), C14H9
(phenanthrenyl), C14H9 (anthracenyl), and C16H9 (pyrenyl)) compounds. All the E1/2 values of the
PPh2Ar compounds compare well to the free PAH E1/2 values previous reported.44,45 The E1/2
values of the PPh2Ar compounds indicate that reduction potentials of the PAH are reversible and
there is no significant steric crowding, electron donation or removal to shift the reduction
potential cathodically or anodically. The E1/2 value of PPh2Ar (Ar = C10H7, naphthyl) was not
reported because the reduction did not occur within the electrochemical window of THF (see
Supporting Information). Figure 5 is a representative cyclic voltammogram of PPh2(1-pyrenyl)
compounds showing scan rate dependence of reversible reduction of the PAH with return
oxidation.
Table 6. Reduction potentials (V vs Fc/Fc+) of PPh2Ar, Ar = C10H7 (naphthyl), C14H9
(phenanthrenyl), C14H9 (anthracenyl), and C16H9 (pyrenyl), at room temperature in THF.
22

PPh2Ar
1-naphthyl
E1/2 vs. Fc/Fc+
(−3.10)a
9-phenanthrenyl
9-anthracenyl
1-pyrenyl
−2.73, (−2.89)a
−2.43 , −2.23, (−2.37)a
−2.38, (−2.40)a
aValues in parentheses represent E1/2 potentials of the free
alternate aromatic hydrocarbon.
1000 mV/s
500 mV/s
250 mV/s
100 mV/s
50 mV/s
-1.50
-2.00
-2.50
-3.00
Potential (V vs. Fc/Fc+)
Figure 5. Representative cyclic voltammogram of PPh2Ar, Ar = 1-pyrenyl, displaying reversible
one electron reduction of pyrene with scan rate dependence in THF.
X-ray Crystallographic analysis. Upon a search of the Cambridge Crystallographic Database
Center, CCDC, the only arylphosphine chalcogenides were the triphenylphosphine
chalcogenides. First, we compared the four sulfur triarylphosphine complexes, 1-4, Table 7.
23

Table 7. Selected bonds lengths and angles of complexes 1-4.
Bond distance
(Å)/angle (°)
1
2
3
4
Ph3PS
P1-S1
P1-C (Phenyl)
P1-C (PAH)
1.9856(2)
1.8213(15)
1.8151(14)
112.88
1.9573(7)
1.8167(18)
1.8212(18)
113.22
1.9535(14)
1.825(3)
1.828(3)
112.75
1.959(3)
1.817(6)
1.815(6)
112.86
1.9528(9)
1.8218(17)
-
113.09
-
S-P-C (Phenyl) average
S-P-C (PAH)
113.82(5)
113.09(6)
116.12(11)
115.3(2)
Compound 1 has a sulfur phosphorus bond length ~0.03 Å longer than that of the other
sulfide complexes, 2-4, including the triphenylphosphine sulfide with a bond length of 1.9528(9)
Å.46 All other structural features are comparable to triphenylphosphine sulfide. For compounds
5-8, the bond distances for the four selenide compound are highlighted in Table 8 and show very
similar bond distances and angles to Ph3PSe.47 The bond lengths and the bond angles of
compounds 9 and 10 are highlighted in Table 9. The structural data for 9 and 10 compare well
with previously reported gold(I) phosphine sulfide and selenide adduct complexes.48
Table 8. Selected bonds lengths and angles of complexes 5-8.
Bond distance (Å)/angle
(°)
5
6
7
8
Ph3PSe
P1-Se1
P1-C (Phenyl)
P1-C (PAH)
2.1194(2)
1.8186(2)
1.8198(2)
113.34
2.1104(13)
1.824(5)
1.814(6)
113.43
2.1045(19)
1.825(6)
1.815(6)
114.59
2.1186(4)
1.8168(17) 1.826(13)
1.8214(16)
112.50
114.90(5)
2.106(1)
-
Se-P-C (Phenyl) average
Se-P-C (PAH)
113.13(8)
-
111.76
112.89(17)
113.1(2)
24

Table 9. Selected bonds lengths and angles of complexes 9 and 10.
Bond distance (Å)/angle (°)
Au1-Cl1
9
10
Ph3PS-AuCl Ph3PSe-AuCl
2.2824(12)
2.2744(12)
2.0256(16)
177.08(4)
100.85(6)
2.284(4)
2.3829(19)
2.176(4)
177.25(12)
92.71(12)
2.285(6)
2.285(5)
2.017(8)
175.84(18)
105.6(3)
2.277(6)
2.371(2)
2.187
178.6(1)
100.1(1)
Au1-E1 (E = S or Se)
P1-E1 (E = S or Se)
E1-Au1-Cl1
P1-E1-Au1
The crystal structures for 1-4 are shown in Figures 6-9, respectively, while the structures for
5-8 can be found in the Supporting Information. Interestingly, as seen in the oxide complex, the
anthracenyl derivatives, 3 and 7, show deviation from planarity in the anthracene ring. These
deviations are small, 3° and 5°, and compare well with the 3° twist of OPPh2(9-anthacenyl).18
The crystal structures of 9 and 10 are featured in Figures 10 and 11, respectively, highlighting
the coordination motif of chalcogenide to gold metal center.
Figure 6. Thermal ellipsoid plot of 1 shown at the 50% probability level. Hydrogen atoms and
solvent molecules have been removed for clarity.
25

Figure 7. Thermal ellipsoid plot of 2 shown at the 50% probability level. Hydrogen atoms and
solvent molecules have been removed for clarity.
Figure 8. (Left) Thermal ellipsoid plot of 3 shown at the 50% probability level. Hydrogen atoms
and other independent molecule have been removed for clarity. (Right) 3 oriented to show the 3°
degree bend in the anthracenyl ring.
26

Figure 9. Thermal ellipsoid plot of 4 shown at the 50% probability level. Hydrogen atoms have
been removed for clarity.
Figure 10. Thermal ellipsoid plot of 9 at 50% probability level. Hydrogen atoms and other
independent molecule in the unit cell have been removed for clarity.
27

Figure 11. Thermal ellipsoid of 10 at 50% probability level. Hydrogen atoms, solvent molecules
and other independent molecules in the unit cell have been removed for clarity.
Literature precedent for bent polycyclic aromatic hydrocarbons. Evidence from 3 and 7 by
fluorescence spectroscopy and X-ray crystallography gave reason to search pre-existing
structures and scrutinize if other polycyclic aromatic structures also had a nonplanar motif. Our
search was narrowed to complexes that only contained P(V) since the structures of PPh2Ar did
not show any obvious strain in the ring system. This was assumed to be the case because the ring
systems were either not large enough to cause more steric pressure than phenyl as in the case of
naphthyl,13,49-51 or the orientation of the aromatic group in space was away from the other rings
like phenanthrenyl52,53 and pyrene.8,54 Upon examining the P(V) compounds with anthracenyl
ligands, all structures with a chalcogenide contained a deviation from planarity. The deviation in
the anthracenyl system is presumably due to the increased steric demand around the phosphine
and the steric pressure that a new substituent caused. In Table 10, we highlight some of those
structures and the deviation from planarity caused in the anthracenyl system. None of the
28

referenced structures in Table 10 brought attention to the fact that the anthracene ring showed
bending.
Table 10: Complexes with a 9-anthracenyl (anth) substituent on a triarylphosphine and the
deviation from planarity that is observed in the anthracene ring in that compound.
Complex
CCDC
Deviation from
planarity°
Reference
Number
(dihedral angle)*
7
Eu(hfac)3[OPPh2(anth)]2
9,10-[OPPh2]2(anth)
9,10-[SPPh2]2(anth)
9,10-[SePPh2]2(anth)
OPPh2(10-Br-anth)
SPPh2(10-Br-anth)
SePPh2(10-Br-anth)
Ph2anthracenyl PO
3
902262
189388
19389
10.2
3.6**
4.3**
4.1**
7.0
25
25
25
55
55
55
18
19390
610421
610422
610423
1005323
12.1
12.1
10
2.6
This work
This work
5.0
7
* When multiple anthracenyl moieties are present, the average is given.
**The major deviations are with C9 and C10 being out of the plane of the anthracene ring.
Only a few reports that included phosphorus ligands highlighted anthracenyl deviating from
planarity.47-52
In
one
case,
a
Au(III)
phosphorus
complex,
3[Au(9,10-
bis(diphenylphosphino)anthracene)], the fluorescence spectrum red-shifted and broadening was
described as being due to excimer formation which we do not observe in the compounds
described here.56
29