Oxidation reactions, coordination chemistry and antibacterial activities with ligand 2-{(diphenylphosphino)methyl}-N,N-dimethylaniline

Article abstract of DOI:10.1016/j.jorganchem.2019.121021

N,N-dimethyl-o-toluidine was treated with n-butyllithium-tmeda in diethylether/hexane solution to give (2-(dimethylamino)benzyl)lithium which reacts with chlorodiphenylphosphine to form the corresponding hemilabile N,P-ligand 2-PPh₂CH₂-1-NMe₂C₆H₄ (1). Oxidation of 1 with elemental sulfur or gray selenium gave the corresponding sulfide and selenide 2-(E)PPh₂CH₂-1-NMe₂C₆H₄ (E = S (2), Se (3)), respectively. The reaction of 1 with M(CO)₆ (M = Mo, W) afforded cis-[Mo(CO)₄{2-PPh₂CH₂-1-NMe₂C₆H₄ }₂](4) and trans-[W(CO)₄{2-PPh₂CH₂-1-NMe₂C₆H₄ }₂](5), respectively. The treatment of 1 with copper(I) iodide in 1:1 mol ratio produced [CuI{2-PPh₂CH₂-1-NMe₂C₆H₄ }]₂ (6). The complexes 4–6 have been screened for antibacterial activity and the results were compared with the activity of the free ligand 1 against four bacterial strains. Complexes 4 and 6 had the highest antibacterial activity and can be considered as promising antimicrobial agents. Compounds 1–6 were characterized by multinuclear NMR spectroscopy (¹H, ¹³C, ³¹P, ⁷⁷Se NMR), IR and elemental analysis. Crystal structure determinations of 1, 2, 4, and 6 were carried out.

Full text of DOI:10.1016/j.jorganchem.2019.121021

Journal of Organometallic Chemistry 905 (2020) 121021
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Oxidation reactions, coordination chemistry and antibacterial
activities with ligand 2-{(diphenylphosphino)methyl}-N,N-
dimethylaniline
Harbi Tomah Al-Masri
Department of Chemistry, Faculty of Sciences, Al al-Bayt University, P.O. Box 130040, Mafraq, 25113, Jordan
a r t i c l e i n f o
a b s t r a c t
Article history:
N,N-dimethyl-o-toluidine was treated with n-butyllithium-tmeda in diethylether/hexane solution to give
(2-(dimethylamino)benzyl)lithium which reacts with chlorodiphenylphosphine to form the corre-
sponding hemilabile N,P-ligand 2-PPh2CH2-1-NMe2C6H4 (1). Oxidation of 1 with elemental sulfur or gray
selenium gave the corresponding sulfide and selenide 2-(E)PPh2CH2-1-NMe2C6H4 (E ¼ S (2), Se (3)),
respectively. The reaction of 1 with M(CO)6 (M ¼ Mo, W) afforded cis-[Mo(CO)4{2-PPh2CH2-1-NMe2C6H4
}2](4) and trans-[W(CO)4{2-PPh2CH2-1-NMe2C6H4 }2](5), respectively. The treatment of 1 with copper(I)
iodide in 1:1 mol ratio produced [CuI{2-PPh2CH2-1-NMe2C6H4 }]2 (6). The complexes 4e6 have been
screened for antibacterial activity and the results were compared with the activity of the free ligand 1
against four bacterial strains. Complexes 4 and 6 had the highest antibacterial activity and can be
considered as promising antimicrobial agents. Compounds 1e6 were characterized by multinuclear NMR
spectroscopy (1H, 13C, 31P, 77Se NMR), IR and elemental analysis. Crystal structure determinations of 1, 2,
4, and 6 were carried out.
Received 4 November 2019
Accepted 6 November 2019
Available online 7 November 2019
Keywords:
Sulfur
Selenium
Tungsten
Molybdenum
Antibacterial
Copper
© 2019 Published by Elsevier B.V.
1. Introduction
these are useful starting materials for main group and transition
metal complexes in which they act as 2KeN,N- or K2eO,N-chelating
The importance of bidentate ligands with 'soft' and 'hard' donor
atoms in homogenous catalysis for industrially important reactions,
coordination chemistry and medicinal chemistry has been the
subject of review papers [1]. The 2KeP,N ligands chosen are known to
exhibit hemilability, whereby at least one of the donors is strongly
coordinating and anchored to the metal, while the more labile
donor(s) can be displaced by catalytic substrates [2]. A number of
complexes of Rh [2e6], Ir [7,8], Ru [9e12], Pd, Pt [13,14] and Re [15]
containing bidentates Ph2P, Me2N-donor ligands with aromatic
backbone have been described. However, no examples of such li-
gands with group 6 metal carbonyls which contain a six- or a
seven-membered chelate ring have been reported to date. Only a
few related examples of the type [M(CO)4{2-PPh2-1-NMe2C6H4 }]
(M ¼ Mo, W) with a five-membered chelate ring have been re-
ported [16].
ligands forming six- and seven-membered chelate rings [18].
We now report the synthesis, spectroscopic properties of 2-
PPh2CH2-1-NMe2C6H4 (1), 2-(E)PPh2CH2-1-NMe2C6H4 (E ¼ S (2),
Se (3)), cis-[Mo(CO)4{2-PPh2CH2-1-NMe2C6H4 }2](4), trans-
[W(CO)4{2-PPh2CH2-1-NMe2C6H4 }2](5) and [CuI{2-PPh2CH2-1-
NMe2C6H4 }]2 (6). The structures of 1, 2, 4 and 6 have been deter-
mined by X-ray crystallography.
2. Experimental section
2.1. General remarks
All experiments were carried out under purified dry nitrogen
using standard Schlenk and vacuum line techniques. Solvents were
dried and freshly distilled under nitrogen [19]. The chemicals
Mo(CO)6, W(CO)6, CuI, n-BuLi, and N,N-dimethyl-o-toluidine were
used as purchased. Infrared spectra were recorded with a Perki-
nElmer System 2000 FT-IR spectrometer between 4000 and
400 cmꢀ1 using KBr disk. The NMR spectra were recorded at 25 ꢁC
on a Bruker AVANC DRX 400 MHz spectrometer operating at
We previously reported the synthesis and the structurally
characterized 2KeN,N- or K2eO,N-ligands bearing Me2N arm [17], as
E-mail address: harbialmasri@yahoo.com.
https://doi.org/10.1016/j.jorganchem.2019.121021
0022-328X/© 2019 Published by Elsevier B.V.

2
H.T. Al-Masri / Journal of Organometallic Chemistry 905 (2020) 121021
400.17 MHz (1H), 100.63 MHz
(
13C), 161.99 MHz
(
31P) and
of 2 in 65% yield. Mp 83e85 ꢁC. 1H NMR (CDCl3,
d/ppm): 2.31 (s, 6H,
76.36 MHz (77Se) using tetramethylsilane for 1H and 13C, 85% H3PO4
for 31P and Me2Se for 77Se NMR as external standards. For 2 and 6
the NMR spectra were recorded at 25 ꢁC on a Bruker AVANC DRX
300 MHz spectrometer operating at 300.13 MHz (1H), 75.47 MHz
N(CH3)2), 4.01 (d, 3JH-H ¼ 14.4 Hz, 2H, CH2), 6.86e7.69 (m, 14H, C6H4
and C6H5). 13C NMR (CDCl3,
d
/ppm): 34.7 (d, 1JC-P ¼ 51.85 Hz, CH2),
45.3 (s, N(CH3)2), 120.3 (d, JC-P ¼ 2.8 Hz), 123.8 (d, JC-P ¼ 2.9 Hz),
127.4 (d, JC-P ¼ 6.6 Hz), 128.2 (d, JC-P ¼ 2.9 Hz), 128.3 (d, JC-
(
13C). Microanalyses were performed on a Flash 2000 elemental
¼ 5.7 Hz), 131.2 (d, JC-P ¼ 1.7 Hz), 131.4 (d, JC-P ¼ 23.9 Hz), 132.1 (d,
P
analyzer. Melting points were carried out with Gallenkamp Model
apparatus with open capillaries.
JC-P ¼ 48.4 Hz), 133.4 (s), 153.2 (d, JC-P ¼ 6.3 Hz). 31P NMR (CDCl3,
d/
ppm): 44.79 (s, 1P). IR (KBr, cmꢀ1): ύ ¼ 1489 s, 1433 s, 1303 m,
1043 s, 650 s. Anal. calcd. for C21H22NPS: C 71.77; H 6.31; N 3.99%.
Found: C 71.78; H 6.31; N 4.10%.
The antimicrobial activity of selected complexes was evaluated
using four bacterial strains; two Gram positive (Bacillus subtillis
(NCTC-1040) and Staphylococcus aureus (NCTC-7447) and two Gram
negative (Escherichia coli (NCTC-10416) and Salmonella typhi
(NCIMB-9331) bacteria. Bacterial cultures were provided by the
microbiology lab at Al al-Bayt University. Each bacterial strain was
subcultured on nutrient agar medium (Merck, Germany) and
incubated overnight at 37 ꢁC. Disc diffusion method was used to
evaluate the antibacterial activity of each complex. Sterile Matricel
(BBL, cocksville USA) 6.0 mm filter paper discs were impregnated
with 1 mg/ml of each test complex and dried to evaporate the re-
sidual solvent (dimethyl sulfoxide (DMSO)). Imipenem was used as
positive control to ensure the activity of standard antibiotic against
the test organisms. The sample discs, the standard antibiotic discs,
and dried blank disc impregnated with DMSO (negative control)
were placed gently on previously marked zones in the agar plates
pre-inoculated with the test bacteria. The plates were then kept in a
refrigerator at 4 ꢁC for about 24 h upside down to allow sufficient
diffusion of the materials from the discs to the surrounding agar
medium. The plates were then inverted and kept in an incubator at
37 ꢁC for 24 h. After incubation, the antimicrobial activity of the test
complexes was determined by measuring the diameter of the in-
hibition zone around the disc.
2.2.3. 2-{(diphenylphosphinoselenoyl)methyl}-N,N-dimethylaniline
(3)
Compound 3 was synthesized as for 2 by using gray selenium
(0.25 g, 3.13 mmol) instead of elemental sulfur and colorless crys-
tals were obtained in 75% yield. Mp 125e127 ꢁC. 1H NMR (CDCl3,
d
/
3
ppm): 2.91 (s, 6H, N(CH3)2), 4.53 (d, JH-H ¼ 13.21 Hz, 2H, CH2),
7.02e8.06 (m, 14H, C6H4 and C6H5). 13C NMR (CDCl3,
d/ppm): 35.0
1
(d, JC-P ¼ 45.3 Hz, CH2), 45.1 (s, N(CH3)2), 120.3 (d, JC-P ¼ 4.0 Hz),
123.7 (d, JC-P ¼ 3.0 Hz), 127.4 (d, JC-P ¼ 4.04 Hz), 128.2 (d, JC-
¼ 12.1 Hz), 128.3 (d, JC-P ¼ 4.0 Hz), 128.5 (d, JC-P ¼ 12.1 Hz), 131.1 (d,
P
JC-P ¼ 5.0 Hz), 131.2 (d, JC-P ¼ 3.0 Hz), 132.2 (d, JC-P ¼ 9.1 Hz), 153.2 (d,
JC-P ¼ 7.1 Hz). 31P NMR (CDCl3,
1JSeeP ¼ 725.7 Hz). 77Se NMR (CDCl3,
d/ppm): 34.93 (s, 1P,
d
/ppm): 286.53 (d, 1Se,
1JSeeP ¼ 729.6 Hz). IR (KBr, cmꢀ1): ύ ¼ 1429 s, 1433 s, 1296 s, 1095 s,
945 m, 756 m, 695 s, 526 s. Anal. calcd. for C21H22NPSe: C 63.32; H
5.57; N 3.52%. Found: C 63.40; H 5.53; N 3.48%.
2.2.4. cis-Tetracarbonylbis{2-[(diphenylphosphino-KP)methyl)]-
N,N-dimethylaniline}molybdenum (0) (4)
A mixture of compound 1 (1.00 g, 3.13 mmol) and Mo(CO)6
(0.80 g, 3.13 mmol) in n-hexane (80 mL) was refluxed for 12 h to
give a dark brown solution. Solvent was reduced to 10 mL under
reduced pressure. Cooling this solution to 4 ꢁC gave 4 as yellow
2.2. Preparation of 1e6
2.2.1. 2-{(diphenylphosphino)methyl}-N,N-dimethylaniline (1)
A solution of 2.5 M n-BuLi in n-hexane (45.6 ml, 0.114 mol) was
added dropwise to a well-stirred solution containing N,N-dimethyl-
o-toludiene (15 g, 0.114 mol) and N,N,N0,N0-tetramethylethylenedi-
amine (8.61 ml, 0.06 mol) in n-hexane (100 mL). The resulting yel-
low solution was stirred for 3 h at room temperature, after that
PPh2Cl (25.15 g, 0.114 mol) in diethylether (100 mL) was added
dropwise at ꢀ4 ꢁC (salted ice bath). The mixture was then allowed
to reach room temperature and stirred for 2 h. After this time,
ethanol (5 mL) and water (100 mL) were added to quench the re-
action and the product was extracted with ether (3 ꢂ 50 mL) and
dried over sodium sulfate. The solvent was removed under reduced
pressure and the viscous residue was recrystallized from a n-hex-
ane/ethanol solution to give the product as colorless crystals in 85%
crystals in 80% yield. Mp 150e152 ꢁC. 1H NMR (CDCl3,
d/ppm): 2.17
(s, 6H, N(CH3)2), 3.70 (br., 2H, CH2), 6.48e7.20 (m, 14H, C6H4 and
C6H5). 13C NMR (CDCl3,
d
/ppm): 34.16 (t, 1JC-P ¼ 8.05 Hz, CH2), 44.71
(s, N(CH3)2),119.6 (s),122.9 (s),127.1 (s),127.6 (t, JC-P ¼ 4.0 Hz),128.9
(s), 131.0 (t, JC-P ¼ 3.0 Hz), 131.1 (t, JC-P ¼ 6.1 Hz), 135.4 (t, JC-
2
¼ 14.1 Hz), 135.6 (d, JC-P ¼ 14.1 Hz), 153.2 (s), 209.8 (t, JC-
P
¼ 9.1 Hz, C≡Oeq), 216.4 (t, 2JC-P ¼ 8.1 Hz, C≡Oax). 31P NMR (CDCl3,
d/
P
ppm): 34.96 (s, 1P). IR (KBr, cmꢀ1): ύ ¼ 1925 vs, 1861 vs (C^O),
1431 s, 1092 m, 692 s, 584 m. Anal. calcd. for C46H44N2P2MoO4: C
65.25; H 5.24; N 3.31%. Found: C 65.23; H 5.27; N 3.33%.
2.2.5. trans-Tetracarbonylbis{2-[(diphenylphosphino-KP)methyl)]-
N,N-dimethylaniline}tungsten(0) (5)
A mixture of compound 1 (1.00 g, 3.13 mmol) and W(CO)6
(1.10 g, 3.13 mmol) in n-hexane (80 mL) was refluxed for 16 h to give
a dark brown solution. Solvent was removed under reduced pres-
sure and the product extracted into ethanol (15 mL). Cooling this
solution to 4 ꢁC gave 5 as yellow crystals in 65% yield. Mp
yield. Mp 82e84 ꢁC. 1H NMR (CDCl3,
d/ppm): 2.65 (s, 6H, N(CH3)2),
3.58 (br., 2H, CH2), 6.89e7.50 (m, 14H, C6H4 and C6H5). 13C NMR
(CDCl3,
d
/ppm): 30.2 (d, 1JC-P ¼ 15.1 Hz, CH2), 45.1 (s, N(CH3)2), 119.9
(s), 123.3 (d, JC-P ¼ 1.5 Hz), 126.7 (d, JC-P ¼ 2.0 Hz), 128.2 (d, JC-
¼ 7.1 Hz),128.4 (s),130.5 (d, JC-P ¼ 11.0 Hz),132.9 (d, JC-P ¼ 18.2 Hz),
210e212 ꢁC. 1H NMR (CDCl3,
d/ppm): 2.31 (s, 6H, N(CH3)2), 4.08 (br.,
P
133.11 (d, JC-P ¼ 7.0 Hz), 139.1 (d, JC-P ¼ 16.1 Hz), 152.9 (d, JC-
2H, CH2), 6.64e7.42 (m, 14H, C6H4 and C6H5). 13C NMR (CDCl3,
d/
¼ 4.0 Hz),. 31P NMR (CDCl3,
d
/ppm): 9.46 (s, 1P). IR (KBr, cmꢀ1):
ppm): 36.0 (t, 1JC-P ¼ 10.1 Hz, CH2), 44.8 (s, N(CH3)2), 119.6 (s), 122.9
(s), 127.1 (s), 127.6 (t, JC-P ¼ 4.0 Hz), 128.9 (s), 130.4 (s), 132.7 (t, JC-
P
ύ ¼ 1433 s, 1097s, 923 m, 748 m, 696 s, 576 s. Anal. calcd. for
C
21H22NP: C 78.97; H 6.94; N 4.39%. Found: C 78.95; H 6.93; N
¼ 6.0 Hz), 133.2 (t, JC-P ¼ 6.0 Hz), 138.2 (t, JC-P ¼ 19.1 Hz), 153.4 (s),
P
2
4.40%.
203.4 (t, JC-P ¼ 6.0 Hz, 4C^O). 31P NMR (CDCl3,
d/ppm): 22.08 (s,
1
1P, JWeP ¼ 278.6 Hz). IR (KBr, cmꢀ1): ύ ¼ 1863 vs (C^O), 1491 s,
1431 s, 1090 m, 696 s, 615 s, 582 m. Anal. calcd. for C46H44N2P2WO4:
C 59.11; H 4.74; N 3.0%. Found: C 59.12; H 4.72; N 3.11%.
2.2.2. 2-{(diphenylphosphinothioyl}methyl)-N,N-dimethylaniline
(2)
A mixture of 1 (1.00 g, 3.13 mmol) and elemental sulfur (0.10 g,
3.13 mmol) in dry toluene (50 mL) was refluxed for 4 h. The solution
was filtered through Celite while hot and the solvent was reduced
to 10 mL and kept at room temperature to afford off-white crystals
2.2.6. Di-m-iodobis{2-[(diphenylphosphino-KP)methyl)]-N,N-
dimethylaniline-KN}di-copper (6)
A mixture of CuI (0.60 g, 0.42 mmol) and ligand 1 (1.00 g,

H.T. Al-Masri / Journal of Organometallic Chemistry 905 (2020) 121021
3
3.13 mmol) in acetonitrile (70 mL) was stirred at room temperature
for 5 h. The reaction solution was evaporated under vacuum and
the desired complex was obtained as white solids. Recrystallization
from dichloromethane/n-hexane gave complex 1 as colorless
previously synthesized without disclosure of spectral data [22a]
according to reported procedure for 2-PPh2-1-NMe2CH2C6H4
ligand [22b]. In this study the ligand was synthesized by a modified
version of a literature method [22b] and fully characterized by
multinuclear NMR spectroscopy, IR, elemental analysis and single
crystal X-ray diffraction. The oxidation reaction of 1 with elemental
sulfur or gray selenium in toluene gives the corresponding sulfide 2
and selenide 3, respectively, as illustrated in Scheme 1.
The reaction of ligand 1 with M(CO)6 (M ¼ Mo, W) under reflux
in n-hexane afforded cis-[Mo(CO)4{2-PPh2CH2-1-NMe2C6H4 }2] (4)
and trans-[W(CO)4{2-PPh2CH2-1-NMe2C6H4 }](5). Moreover, The
treatment of 1 with cuprous iodide in 1:1 mol ratio afforded [CuI{2-
PPh2CH2-1-NMe2C6H4 }]2 (6) (Scheme 1).
crystals in 70% yield. Mp 207e209 ꢁC. 1H NMR (CDCl3,
d
/ppm): 2.86
(s, 12H, N(CH3)2), 3.68 (br., 4H, CH2), 6.77e7.56 (m, 28H, C6H4 and
C6H5). 13C NMR (CDCl3,
/ppm): 33.0 (s, CH2), 47.2 (s, N(CH3)2), 119.1
d
(s), 123.6 (s), 127.7 (s), 128.0 (d, JC-P ¼ 23.6 Hz), 128.3 (s), 129.7 (s),
132.5 (s), 132.7 (s), 133.5 (d, JC-P ¼ 13.5 Hz), 152.3 (s). 31P NMR
(CDCl3,
d
/ppm): 32.87 (s, 1P). IR (KBr, cmꢀ1): ύ ¼ 1489 s, 1437 s,
1097 m, 695 s, 582 m. Anal. calcd. for C42H44N2P2Cu2: C 65.87; H
5.79; N 3.66%. Found: C 65.80; H 5.74; N 3.64%.
Compounds 1e6 were isolated and fully characterized by
multinuclear NMR spectroscopy, IR and elemental analysis.
Furthermore, the molecular structures of 1, 2, 4, and 6 were eluci-
dated by single crystal X-ray diffraction.
2.3. Data collection and structure determination
Crystallographic data are given in Table 1. Single-crystal X-ray
diffraction data were collected using MoKa radiation (
l
¼ 0.71073 Å)
on an Xcalibur-Eos-Gemini diffractometer. Crystals were main-
tained at 293K during data collection. Using Olex2 [20], The
structures were solved with the ShelXT [21] structure solution
program using Intrinsic Phasing and refined with the ShelXL [21]
refinement package using Least Squares minimization. The Crys-
tallographic data (excluding structure factors) have been deposited
with the Cambridge Crystallographic Data Centre, CCDC, 12 Union
Road, Cambridge CB21EZ, UK. Copies of the data can be obtained
free of charge on quoting the depository numbers CCDC-1952201
for 1, CCDC-1952202 for 2, CCDC-1952203 for 4 and CCDC-1952204
for 6 (Fax: þ44-1223-336-033; E-Mail: deposit@ccdc.cam.ac.uk,
http://www.ccdc.cam.ac.uk).
3.2. 1H, 13C, 31P, 77Se NMR and IR spectra
In the 1H NMR spectrum, the most noticeable resonance is that
due to the N(CH3)2 protons, which show a singlet for each com-
pounds at 2.65 (1), 2.31 (2), 2.91 (3), 2.17 (4), 2.31 (5) and 2.68 ppm
(6). The resonances corresponding to the benzylic protons are
observed as broad singlets (3.58 (1), 3.70 (4), 4.08 (5)), doublets
(4.01 (2), 4.53 (3)) and a well resolved singlet (3.68 (6)).
The 13C NMR spectra of 1e6 reveal the resonances of the
N(CH3)2 carbon atoms which exhibit resonances at 45.1 (1), 45.3
(2), 45.1 (3), 44.7 (4), 44.8 (5) and 47.2 ppm (6). Moreover, the
resonances corresponding to the methylene carbon atoms are
observed at 30.2 (1), 34.7 (2), 35.0 (3) as doublets, 34.2 (4), 36.0 (5)
as triplets and 33.0 (6) as singlet. The 1H NMR (6.48e7.78 ppm) and
13C NMR (119.1e153.8 ppm) signals of the phenyl groups are in the
expected range.
3. Results and discussion
3.1. Synthesis
N,N-dimethyl-o-toluidine was treated with n-butyllithium-
tmeda in ether/hexane solution for 2e3 h to afford the (2-(dime-
thylamino)benzyl)lithium intermediate which was further reacted
with PPh2Cl compound to give the corresponding 2-((diphenyl-
phosphino)methyl)-N,N-dimethylaniline (1). This compound was
Interestingly, in 4 and 5, the ligand behaves as KP-coordination
mode rather than 2KP,N-mode. The non-occurrence of 2KP,N-mode is
unambigously due to reaction condition, and may be obtained if the
reaction is carried out at higher temperatures and for longer time. It
is interesting that intramolecular binding of the ammine is clearly
Table 1
Crystal data and structure refinement for 1, 2, 4 and 6.
1
2
4
6
Formula
Mr
Temp [K]
Crystal system
Space group
a [Å]
C42H44N2P2
638.73
293(2)
monoclinic
P 21/c
20.6885(11)
9.1084(6)
19.7458(12)
90
105.199(6)
90
3590.7(4)
4
C21H22NPS
351.42
293(2)
monoclinic
P 21/n
9.5400(4)
14.2269(5)
14.0999(4)
90
97.268(3)
90
1898.33(12)
4
C46H44MoN2O4P2
846.71
293(2)
triclinic
ꢀ
P ı
9.3720(5)
10.6896(5)
22.8077(11)
87.189(4)
89.573(4)
73.394(5)
2187.0(2)
2
C42H44Cu2I2N2P2
1019.61
293(2)
monoclinic
P 21
10.3547(8)
12.5513(6)
16.3110(9)
90
107.327(7)
90
2023.7(2)
2
b [Å]
c [Å]
a
b
g
[ꢁ]
[ꢁ]
[ꢁ]
V [Å3]
Z
rcalcd (Mg mꢀ3
F(000)
)
1.182
1360
0.153
1.230
744
0.256
1.286
876
0.416
1.673
1008
2.687
Abs coeff (mmꢀ1
)
No. of rflns coll.
No. of indep rflns
Rint
17246
8312
0.0236
415
17417
4659
0.0263
217
19261
10108
0.0292
497
17903
9353
0.0228
452
No. of parameters
R1 (I > 2
wR2 (all data)
s
(I))
0.0498
0.1331
0.471
0.0430
0.1128
0.366
ꢀ0.344
0.0429
0.0948
0.368
ꢀ0.365
0.0306
0.0693
0.582
ꢀ0.735
(
D/
r)
[e.Åꢀ3
]
]
max
(
D/
r)
[e.Åꢀ3
- 0.226
min

4
H.T. Al-Masri / Journal of Organometallic Chemistry 905 (2020) 121021
Scheme 1. Preparation of 2e6.
much slower than is intramolecular binding of a second P donor
under the reaction conditions employed. Further studies are in
progress to investigate the coordination chemistry of ligand 1. The
13C NMR spectra of the carbonyl ligands in 4 show two signals
(209.8 and 216.4 ppm) due to the carbonyls oriented trans and cis to
phosphorus atoms. In contrast, the four carbonyl ligands in 5 are
equivalent and gave one signal at 203.4 ppm, typical of the two
phosphorus ligands being trans to each other. Consistent with these
results, The IR spectra in the carbonyl region of 4 show two peaks at
2021 cmꢀ1 and doublet type band at 1900 and 1867 cmꢀ1, while in
5 only one doublet type band at 1874 and 1903 cmꢀ1 was observ-
able for the four equivalent carbonyl ligands and within the ex-
pected value range on comparison to similar cis- and trans-
disubsituted complexes [23]. The IR spectrum of 1ꢀ6 shows bands
coupling constant of 278.6 Hz.
3.3. Molecular structures of 1, 2, 4, and 6
Crystals of 1, 2, 4, and 6 were obtained as described in the
experimental section. Compounds 1, 2, 4, and 6 crystallize in the
monoclinic space group P21/c, monoclinic space group P21/n,
ꢀ
triclinic space group P ı, and monoclinic space group P21, respec-
tively. The molecular structures of 1, 2, 4, and 6 are depicted in
Fig. 1e4, respectively.
Selected bond distances [Å] and angles [ꢁ] 1a: C(1)eN(1) 1.468(2);
C(2)eN(1) 1.458(3); C(3)eN(1) 1.431(2); C(9)eP(1) 1.8562(19);
C(10)eP(1) 1.833(2); C(16)eP(1) 1.837(2); C(4)-C(3)-N(1) 121.95(17);
C(8)-C(3)-N(1) 119.57(16); C(8)-C(9)-P(1) 112.33(13); C(11)-C(10)-
P(1) 125.82(15); C(15)-C(10)-P(1) 116.75(17); C(21)-C(16)-P(1)
118.07(16); C(17)-C(16)-P(1) 123.86(16); C(10)-P(1)-C(16) 101.09(8);
C(10)-P(1)-C(9) 101.66(9); C(16)-P(1)-C(9) 102.26(9); C(3)-N(1)-C(2)
114.13(16); C(3)-N(1)-C(1) 115.09(17); C(2)-N(1)-C(1) 109.84(18).
Selected bond distances [Å] and angles [ꢁ] 1b: C(22)eN(2)
1.464(3); C(23)eN(2) 1.463(2); C(24)eN(2) 1.428(2); C(30)eP(2)
1.8560(18); C(31)eP(2) 1.836(2); C(37)eP(2) 1.832(2); C(25)-C(24)-
N(2) 121.91(16); C(29)-C(24)-N(2) 119.44(17); C(29)-C(30)-P(2)
in the range of 1431e1437 cmꢀ1 due to
y(PꢀPh) stretching [24].
Also, the P]S double bond in 2 exhibits vibrations around
650 cmꢀ1, whereas band at around 526 cmꢀ1 that is characteristic
of P]Se double bond is observed in 3 [25].
The 31P NMR spectrum of 1 shows a single resonance at
d
¼ -
9.46 ppm, while the 31P NMR signals of 2e6 appear as a singlet at
d
d
¼ 44.79 ppm (2),
d
d
¼ 34.93 ppm (3),
d
¼ 34.96 ppm (4),
¼ 22.08 ppm (5) and
¼ 32.87 ppm (6), i.e. shifted downfield in
comparison with the parent organic ligand 1, and a move to lower
chemical shifts is observed with the decreasing electronegativity of
the chalcogen from sulfur to selenium.
112.48(13);
C(32)-C(31)-P(2)
118.51(17);
C(36)-C(31)-P(2)
123.97(15); C(42)-C(37)-P(2) 125.58(15); C(38)-C(37)-P(2) 116.83(1;
C(37)-P(2)-C(31) 98.87(8); C(37)-P(2)-C(30) 102.59(9); C(31)-P(2)-
C(30) 103.00(9); C(24)-N(2)-C(23) 115.23(17); C(24)-N(2)-C(22)
113.51(15); C(23)-N(2)-C(22) 110.24(17).
The 31P NMR signal of 3 is flanked by two 77Se-satellites with
1JSeeP coupling constant of 725.7 Hz. The 77Se NMR spectrum of 3
Selected bond distances [Å] and angles [ꢁ] 2: S(1)eP(1)
1.9591(6); P(1)eC(10) 1.8110(17); P(1)eC(16) 1.8122(17); P(1)eC(9)
1.8298(16); N(1)eC(3) 1.429(2); N(1)eC(1) 1.459(3); N(1)eC(2)
1.461(2); C(10)-P(1)-C(16) 103.52(7); C(10)-P(1)-C(9) 105.85(8);
shows a doublet at
d
¼ ꢀ286.6 ppm and the value of coupling
constant (1JSeeP ¼ 729.6 Hz) match the difference value between
the two 77Se-satellites in the 31P NMR spectrum of 3. Moreover, the
31P NMR signal of 5 is flanked by two 183W-satellites with JWeP
1

H.T. Al-Masri / Journal of Organometallic Chemistry 905 (2020) 121021
5
Fig. 3. Molecular structure of 4 (hydrogen atoms are omitted for clarity).
Fig. 1. Molecular structure of the two independent molecules 1a (above) and 1b
(down) (hydrogen atoms are omitted for clarity).
Fig. 4. Molecular structure of 6 (hydrogen atoms are omitted for clarity).
C(45) 2.041(3); Mo(01)eP(1) 2.5471(7); Mo(01)eP(2) 2.5897(6);
P(1)eC(16) 1.827(3); P(1)eC(10) 1.828(2); P(1)eC(9) 1.858(2); P(2)e
C(31)1.837(3);P(2)eC(37)1.839(3);P(2)eC(30)1.856(2);O(1)eC(43)
1.137(3); O(2)eC(44) 1.147(3); O(3)eC(45) 1.143(3); O(4)eC(46)
1.146(3); N(1)eC(3) 1.427(5); N(1)eC(1) 1.455(5); N(1)eC(2)
1.467(5); N(2)eC(22) 1.435(4); N(2)eC(24) 1.435(4); N(2)eC(23)
1.449(4); C(46)-Mo(01)-C(44) 87.55(11); C(46)-Mo(01)-C(43)
85.01(11); C(44)-Mo(01)-C(43) 92.34(11); C(46)-Mo(01)-C(45)
85.57(12); C(44)-Mo(01)-C(45) 87.43(11); C(43)-Mo(01)-C(45)
170.57(11);
C(46)-Mo(01)-P(1)
86.15(8);
C(44)-Mo(01)-P(1)
173.30(7); C(43)-Mo(01)-P(1) 89.39(7); C(45)-Mo(01)-P(1) 89.80(8);
C(46)-Mo(01)-P(2)174.68(8); C(44)-Mo(01)-P(2) 88.86(7); C(43)-
Mo(01)-P(2) 99.07(7); C(45)-Mo(01)-P(2) 90.35(8); P(1)-Mo(01)-
P(2) 97.27(2); C(16)-P(1)-C(10) 105.57(12); C(16)-P(1)-C(9)
101.68(12);
C(10)-P(1)-C(9)
105.88(12);
C(16)-P(1)-Mo(01)
121.99(8); C(10)-P(1)-Mo(01) 110.14(8); C(9)-P(1)-Mo(01) 110.27(9);
C(31)-P(2)-C(37) 104.48(13); C(31)-P(2)-C(30) 102.50(11); C(37)-
P(2)-C(30) 103.22(12); C(31)-P(2)-Mo(01) 122.99(9); C(37)-P(2)-
Mo(01) 112.64(8); C(30)-P(2)-Mo(01) 108.92(8); C(3)-N(1)-C(1)
114.2(3); C(3)-N(1)-C(2) 115.4(4); C(1)-N(1)-C(2) 112.4(4); C(22)-
N(2)-C(24) 112.6(3); C(22)-N(2)-C(23) 111.5(3); C(24)-N(2)-C(23)
115.8(3); O(1)-C(43)-Mo(01) 173.9(2); O(2)-C(44)-Mo(01) 176.0(2);
O(3)-C(45)-Mo(01) 173.1(3); O(4)-C(46)-Mo(01) 178.1(3).
Fig. 2. Molecular structure of 2 (hydrogen atoms are omitted for clarity).
C(16)-P(1)-C(9)104.57(7); C(10)-P(1)-S(1) 114.12(6); C(16)-P(1)-
S(1)
112.61(6);
C(9)-P(1)-S(1)
115.06(6);
C(3)-N(1)-C(1)
114.98(16); C(3)-N(1)-C(2) 112.91(16); C(1)-N(1)-C(2) 111.20(18).
Selected bond distances [Å] and angles [ꢁ] 4: Mo(01)eC(46)
1.975(3); Mo(01)eC(44) 1.985(3); Mo(01)eC(43) 2.034(3); Mo(01)e
Selected bond distances [Å] and angles [ꢁ] 6: Cu(1)eP(1)

6
H.T. Al-Masri / Journal of Organometallic Chemistry 905 (2020) 121021
2.199(4); Cu(1)eI(1) 2.575(3); Cu(1)eI(2) 2.596(2); Cu(1)eCu(2)
2.9274(7); Cu(2)eP(2) 2.202(4); Cu(2)eI(2) 2.579(3); Cu(2)eI(1)
2.589(2); P(1)eC(9) 1.818(16); P(1)eC(16) 1.825(14); P(1)eC(10)
1.830(14); P(2)eC(37) 1.795(14); P(2)eC(31) 1.820(12); P(2)eC(30)
1.876(14); P(1)-Cu(1)-I(1) 124.59(14); P(1)-Cu(1)-I(2) 119.26(14);
I(1)-Cu(1)-I(2) 110.96(7); P(1)-Cu(1)-Cu(2) 158.75(13); I(1)-Cu(1)-
Cu(2) 55.69(4); I(2)-Cu(1)-Cu(2) 55.27(6); P(2)-Cu(2)-I(2)
124.28(14); P(2)-Cu(2)-I(1) 119.42(14); I(2)-Cu(2)-I(1) 111.07(8);
P(2)-Cu(2)-Cu(1) 158.65(12); I(2)-Cu(2)-Cu(1) 55.83(4); I(1)-Cu(2)-
Cu(1) 55.23(6); Cu(1)-I(1)-Cu(2) 69.08(7); Cu(2)-I(2)-Cu(1)
68.90(7); C(9)-P(1)-C(16) 106.8(6); C(9)-P(1)-C(10) 101.5(6);
C(16)-P(1)-C(10) 101.8(6) C(9)-P(1)-Cu(1) 109.1(5); C(16)-P(1)-
Cu(1) 116.3(5); C(10)-P(1)-Cu(1) 119.9(5); C(37)-P(2)-C(31)
104.2(6); C(37)-P(2)-C(30) 107.2(7); C(31)-P(2)-C(30) 101.6(6);
C(37)-P(2)-Cu(2) 115.8(5); C(31)-P(2)-Cu(2) 118.7(4); C(30)-P(2)-
Cu(2) 108.0(5); C(3)-N(1)-C(1) 116.7(12); C(3)-N(1)-C(2)
105.6(11); C(1)-N(1)-C(2) 107.2(11); C(22)-N(2)-C(24) 118.1(13);
C(22)-N(2)-C(23) 111.3(12); C(24)-N(2)-C(23) 113.1(12).
As in solution, 6 forms a centrosymmetric dimer in the solid
state (Fig. 4) in which the central four-membered Cu2I2 ring is
planar with smaller CueIeCu [69.08(7) and 68.90(7)ꢁ] and larger
IeCueI [110.96(7) and 111.07(8)ꢁ] bond angles. Due to the presence
of an inversion center, only the anti isomer is observed in the solid
state. The CueIeCu angles in
6 are larger than those in
[{Ph2P(C6H4CH2NMe2-o)}(CuI)]2 [Av. 67.01(2)ꢁ], while the situation
is reversed for the IeCueI angles. Apparently, the presences of the
NMe2 groups increase the CueIeCu bond angle, presumably as a
result of steric effects. The anti arrangement of the two NMe2
methyl groups with respect to the Cu2I2 core in 6 is similar to the
anti alignment of the two NMe2 methyl groups with respect to the
Cu2I2 core in [{Ph2P(C6H4CH2NMe2-o)}(CuI)]2 [30] and differs from
The syn arrangement of the two NMe2 methyl groups in
[{Ph2P(C6H4NMe2-o)}(CuI)]2 [31]. However, in the latter, the CueI
[Av. 2.618 Å] bonds are smaller than those of 6 [Av. 2.660 Å].
The X-ray crystal structure determination shows a distorted
tetrahedral environment of the four-coordinate Cu atoms. The
tetrahedral distortion of the environment of the Cu atoms in 6 can
be attributed to repulsion between the dimethylamino and phenyl
groups.
The X-ray structure of 1 contains two crystallographically in-
dependent molecules, 1a and 1b (Fig. 1), in the asymmetric unit.
The molecular structures of 1a and 1b show pyramidal geometry
about the phosphorus atoms with the CePeC angles ranging from
98.87(8) ꢀ 103.00(9)ꢁ.
3.4. Antibacterial activities
The molecular structure of 2 shows a distorted tetrahedral ge-
ometry about the phosphorus atom with SePeC and CePeC angles
ranging from 103.52(7)ꢀ115.06(6)ꢁ. The P]S [1.9591(6) Å] bond
length in 2 is similar to those observed for [2-(Me2NCH2)C6H4]3P(S)
[1.962(2) Å] and [2-(Me2NCH2)C6H4]2PhP(S) [1.9547(10) Å] (8) [26].
The crystal structure of 4 (Fig. 3) shows a distorted octahedral
environment around the Mo-metal surrounded by four terminal CO
ligands and two phosphorus atoms of the two cis-oriented P,N-li-
gands with two types of carbonyl ligands have different MoeC
bond distances.
The carbonyl groups cis to the phosphorus atoms of the P,N-li-
gands are bound at 2.034(3) Å and 2.041(3) Å, while the other two
carbonyl groups are closer to the metal center at distances of
1.975(3) Å and 1.985(3) Å. The two MoeP bond distances [2.5471(7)
and 2.5897(6) Å] in 4 are relatively similar. The steric interaction of
the two P,N-ligands has affected the dimensions of the Mo(CO)4
portion of the molecule. The P(l)-Mo-P(2) angle of 97.27(2)ꢁ is
largely expanded from the right angle of 90ꢁ, while the C(46)-Mo-
C(43) angle of 85.01 (11)ꢁ is a significantly smaller than the ideal
angle of 90ꢁ and greater distortion involving the carbonyl groups
CO(2) and CO(3). The C(46)-Mo-P(1) angle of 86.15(8)ꢁ and the
C(44)-Mo-P(2) angle of 88.86(7)ꢁ are representative of the tilting of
the O(1)-Mo-O(3) axial with respect to the P(1), P(2), Mo, C(46),
C(44) plane.
The ligand (1) and its metal derivatives 4, 5 and 6 were screened
for their antibacterial activities using disc diffusion method. Imi-
penem was used as standard antibiotic which had been compared
with the activities of the complexes. Imipenem had an excellent
activity against both Gram-positive and Gram-negative bacteria. As
shown in Table 2, complexes 4, 5 and 6 showed more potent anti-
bacterial activity against Gram positive bacteria than the free ligand
1. This variation can be attributed to combined effect of metal atom
and the ligand, which enhances the diffusion of metal complexes as
a whole through the lipid layers of cell membrane and/or binding to
the protein synthesizing enzyme thus restrained the protein syn-
thesis for bacterial growth of microorganism [32].
All complexes showed almost the same activity against Gram
negative bacteria which may be attributed to the nature of the cell
wall of the Gram negative bacteria. Complexes 4 and 6 had more
antibacterial potential than complex 5 against Gram positive bac-
teria. Staphylococcus aureus was resistant to ligand 1 and complex 5,
and susceptible to complexes 4 and 6. The highest susceptibility
was observed for the Bacillus subtilis in the case of using complex 6,
with an inhibition zone of 20 mm, which indicates that this com-
plex could be used as growth control of this bacterium. Compared
with the standard antibiotic, all complexes showed overall good
activity against Salmonella typhi suggesting that these complexes
can be used for controlling the growth of this pathogen.
The MoeP bond distances and the P(l)-Mo-P(2) bond angle in 4
are larger than those found in similar cis-[Mo(CO)4{PPh2NH2}2] [Av.
MoeP: 2.526 Å; PeMoeP: 90.06(2)ꢁ ] [27], cis-[Mo(CO)4{PPh2NH-
But}2] [Av. MoeP: 2.545 Å; PeMoeP: 95.44(3)ꢁ ] [28] and cis-
[Mo(CO)4{Ph,PCH2NHC6H5Me-4}2] [Av. MoeP: 2.546 Å; PeMoeP:
94.2(1)ꢁ ] [29] complexes.
4. Conclusion
In conclusion, we have successfully synthesized ligand 1 (2-
PPh2CH2-1-NMe2C6H4), and their derivatives 2-(E)PPh2CH2-1-
Table 2
Antibacterial activity (inhibition zones, mm) of ligand 1 and its metal derivatives 4e6 (1 mg/ml concentration) against selected bacteria.
Compound
Bacteria
Bacillus subtilis
Staphylococcus aureus
Escherichia coli
Salmonella typhi
1
4
5
6
10
20
13
23
25
NA
15
NA
15
24
16
18
16
18
26
20
20
19
20
23
Imipenem
Values are the average diameters of the inhibition zones (mm). NA: No Activity observed.

H.T. Al-Masri / Journal of Organometallic Chemistry 905 (2020) 121021
7
284e289.
NMe2C6H4 (E ¼ S (2), Se (3)), cis-[Mo(CO)4(1)] (4), trans-
[W(CO)4(1)] (5) and [CuI(1)]2 (6). The ligand behaves as KP-coor-
dination mode rather than 2KP,N-mode due to reaction condition,
and may be obtained if the reaction is carried out at higher tem-
peratures and for longer time. Further studies are in progress to
investigate the coordination of ligand 1. For 1, 2, 4 and 6 the mo-
lecular structures are determined. Based on the antibacterial re-
sults, we conclude that all compounds 1 and 4e6 were good
antibacterial agents against both Gram positive and Gram negative
bacteria. Complexes 4 and 6 present the highest antibacterial ac-
tivity and can be considered as promising antimicrobial agents.
[8] T.B. Rauchfuss, J.L. Cements, S.F. Agnew, D.M. Roundhill, Inorg. Chem. 16
(1977) 775e778.
[9] X. Yu, B.O. Patrick, B.R. James, Organometallics 25 (2006) 4870e4877.
[10] D.A. Cavarzan, F.R. Caetano, L.L. Romualdo, F.B. do Nascimento, A.A. Batista,
J. Ellena, A. Barison, M.P. de Araujo, Inorg. Chem. Commun.
1247e1250.
[11] J. Schroer, L.V.P. da Cunha, A.A. Batista, V.M. Deflon, U. Abram, Polyhedron 34
(2012) 108e113.
[12] L.J. Hounjet, M. Bierenstiel, M.J. Ferguson, R. McDonald, M. Cowie, Inorg.
Chem. 49 (2010) 4288e4300.
[13] L. Crociani, G. Bandoli, A. Dolmella, M. Basato, B. Corain, Eur. J. Inorg. Chem.
(1998) 1811e1820.
[14] D. Hedden, D.M. Roundhill, Inorg. Chem. 24 (1985) 4152e4158.
[15] F. Tisato, F. Refosco, C. Bolzati, A. Cagnolini, S. Gatto, G. Bandoli, J. Chem. Soc.,
Dalton Trans. (1997) 1421e1427.
9 (2006)
Declaration of competing interest
The author declare that there is no conflict of interest.
Acknowledgments
[16] L. Dahlenburg, K. Herbst, H. Berke, J. Organomet. Chem. 585 (1999) 225e233.
[17] H.T. Al-Masri, J. Sieler, P. Lonnecke, S. Blaurock, K. Domasevitch, E. Hey-
Hawkins, Tetrahedron 60 (2004) 333e339.
[18] a) H.T. Al-Masri, J. Sieler, E. Hey-Hawkins, Appl. Organomet. Chem. 17 (2003)
€
63e67;
b) H.T. Al-Masri, J. Sieler, E. Hey-Hawkins, Appl. Organomet. Chem. 17 (2003)
641e646;
€
c) H.T. Al-Masri, J. Sieler, P. Lonnecke, P.C. Junk, E. Hey-Hawkins, Inorg. Chem.
I would like to thank the Deanship of Scientific Research at Al al-
Bayt University\ Jordan for funding (grant number 8635/2017). I
would also like to thank Prof. Munther khanfor, Dr. Taghleb and Dr.
Ziad for their help and support. The X-ray of compounds 1, 2, 4 and
6 were provided by Homdi Mango Research center (HMRC), Jordan
University, Jordan.
43 (2004) 7162e7169;
d) H.T. Al-Masri, J. Sieler, P.C. Junk, K. Domasevitch, E. Hey-Hawkins,
J. Organomet. Chem. 690 (2005) 469e476;
€
e) H.T. Al-Masri, J. Sieler, S. Blaurock, P. Lonnecke, P. Junk, E. Hey-Hawkins,
Z. Anorg. Allg. Chem. 631 (2005) 518e523;
f) H.T. Al-Masri, J. Baldamus, E. Hey-Hawkins, Polyhedron 28 (2009)
3515e3518.
[19] D.D. Perrin, W.L.F. Armarego, Purification of Laboratory Chemicals, third ed.,
Pergamon, New York, 1988.
Appendix A. Supplementary data
[20] O.V. Dolomanov, L.J. Bourhis, R.J. Gildea, J.A.K. Howard, H. Puschmann, J. Appl.
Crystallogr. 42 (2009) 339e341.
[21] G.M. Sheldrick, Sheldrick, Acta Crystallogr. A71 (2015) 3e8.
[22] a) J. Andrieu, P. Richard, J.M. Camus, R. Poli, Inorg. Chem. 41 (15) (2002)
3876e3885;
Supplementary data to this article can be found online at
https://doi.org/10.1016/j.jorganchem.2019.121021.
b) T.B. Rauchfuss, F.T. Patino, D.M. Roundhill, Inorg. Chem. 14 (1975) 652e656.
[23] S. Priya, M.S. Balakrishna, J.T. Mague, J. Organomet. Chem. 679 (2003)
116e124.
References
€
€
[24] A. Karacar, M. Freytag, H. Thonnessen, J. Omelanczuk, P.G. Jones, R. Bartsch,
[1] a) P.C. Ford, L. Laverman, Coord. Chem. Rev. 249 (2005) 391e403;
b) P. Espinet, K. Soulantica, Coord. Chem. Rev. 193e195 (1999) 499e556;
c) E. Lindner, S. Pautz, M. Haustein, Coord. Chem. Rev. 155 (1996) 145e162;
d) G.R. Newkome, Chem. Rev. 93 (1993) 2067e2089;
R. Schmeltzer, Heteroat. Chem. 12 (2001) 102e113.
€€
€
[25] L. Hirsivaara, M. Haukka, S. Jaaskelainen, R.H. Laitinen, E. Niskanen,
T.A. Pakkanen, J. Pursiainen, J. Organomet. Chem. 579 (1999) 45e52.
[26] A. Rotar, A. Covaci, A. Pop, A. Silvestru, Rev. Roum. Chim. 55 (11e12) (2010)
823e829.
[27] G.M. Gray, Y. Zhang, J. Crystallogr. Spectrosc. Res. 23 (1993) 711e717.
[28] O. Kühl, S. Blaurock, J. Sieler, E. Hey-Hawkins, Polyhedron 20 (2001) 111e117.
[29] D.L. Davies, F.I. Healey, J. Howarth, D.R. Russell, L.J.S. Sherry, J. Organomet.
Chem. 376 (1989) C31eC34.
e) A. Bader, E. Lindner, Coord. Chem. Rev. 108 (1991) 27e35;
f) S. Maggini, Coord. Chem. Rev. 253 (2009) 1793e1832;
g) J.A. Lemire, J.J. Harrison, R.J. Turner, Nat. Rev. Microbiol. 11 (2013) 371e384.
[2] L.J. Hounjet, R. McDonald, M.J. Ferguson, M. Cowie, Inorg. Chem. 50 (2011)
5361e5378.
€€
€
[3] P. Suomalainen, S. Jaaskelainen, M. Haukka, R.H. Laitinen, J. Pursiainen,
T.A. Pakkanen, Eur. J. Inorg. Chem. (2000) 2607e22613.
[30] G.S. Ananthnag, N. Edukondalu, J.T. Mague, M.S. Balakrishna, Polyhedron 62
(2013) 203e207.
[4] J. Andrieu, P. Richard, J. Camus, R. Poli, Inorg. Chem. 41 (2002) 3876e3885.
[5] T.B. Rauchfuss, D.M. Roundhill, J. Am. Chem. Soc. 96 (1974) 3098e3105.
[6] J. Andrieu, J. Camus, P. Richard, R. Poli, L. Gonsalvi, F. Vizza, M. Peruzzini, Eur. J.
Inorg. Chem. (2006) 51e61.
[31] M.J. Leitl, F.-R. Küchle, H.A. Mayer, L. Wesemann, H. Yersin, J. Phys. Chem. A
117 (46) (2013) 11823e11836.
[32] R.A. Sanchez-Delgado, K. Lazardi, L. Rincon, J.A. Urbina, J. Med. Chem. 36
(1993) 2041e2043.
[7] D.M. Roundhill, R.A. Bechtold, S.G.N. Roundhill, Inorg. Chem. 19 (1980)