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Article

Rearrangement of Diferrocenyl 3,4-Thiophene Dicarboxylate

by
Asma Ghazzy
1,
Deeb Taher
2,*,
Marcus Korb
3,
Khaled Al Khalyfeh
4,
Wissam Helal
2,
Hazem Amarne
2,
Tobias Rüffer
5,
Zakariyya Ishtaiwi
6 and
Heinrich Lang
5,7
1
Faculty of Pharmacy, Al Ahliyya Amman University, Amman 19328, Jordan
2
Department of Chemistry, The University of Jordan, Amman 11942, Jordan
3
School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
4
Department of Chemistry, Faculty of Natural Sciences, Al-Hussein Bin Talal University, Ma’an 71111, Jordan
5
Faculty of Natural Sciences, Institute of Chemistry, Technische Universität Chemnitz, Inorganic Chemistry, D-09107 Chemnitz, Germany
6
Department of Chemistry, Faculty of Science, Al-Balqa Applied University, Al Salt 19117, Jordan
7
MAIN Research Center, Technische Universität Chemnitz, Rosenbergstraße 6, D-09126 Chemnitz, Germany
*
Author to whom correspondence should be addressed.
Inorganics 2022, 10(7), 96; https://doi.org/10.3390/inorganics10070096
Submission received: 23 May 2022 / Revised: 18 June 2022 / Accepted: 22 June 2022 / Published: 6 July 2022
(This article belongs to the Special Issue Inorganics: 10th Anniversary)
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Versions Notes

Abstract

Treatment of 3,4-(ClC(O))2-cC4H2S (1) with [FcCH2OLi] (2-Li) (Fc = Fe(η5-C5H5)(η5-C5H4)) in a 1:2 ratio gave 3,4-(FcCH2OC(O))2-cC4H2S (3). Compound 3 decomposes in solution during crystallization to produce FcCH2OH (2) along with 3,4-thiophenedicarboxylic anhydride (4). The cyclic voltammogram of 3 exhibits a reversible ferrocene-related redox couple (E1/2 = 108 mV, vs. Cp2Fe/Cp2Fe+) using [NnBu4] [B(C6F5)4] as the supporting electrolyte. DFT calculations reveal that the energy values of the LUMO orbitals of 3 (3,4-thiophene core) show 1 eV higher energies than that one of 2,5-(FcCH2OC(O))2-cC4H2S (5), both compounds’ HOMO orbitals are close to each other. Compound 4 was characterized by single X-ray structure analysis. It forms a band-type structure based on intermolecular O1···S1 interactions being parallel to (110) and (1–10) in the solid state, while electrostatic C···O interactions between the C=O functionalities of adjacent molecules connect both 3D-networks. Hirshfeld surface analysis was used to gain more insight into the intermolecular interactions in 4, the enrichment ratios (E) suggest that O···H, S···S, and O···C are the most favored intermolecular interactions, as shown by E values above 1.20. The relevance of the weak O···H, O···O, and O···C contacts in stabilizing the molecular structure of 4 was highlighted by the interaction energies between molecular pairs.

1. Introduction

Since ferrocene’s discovery in 1951, its derivatives have played an increasingly essential role in chemistry during the following few decades [1,2,3,4]. Ferrocene-derived species were inspected broadly within the field of organometallic chemistry, e.g., as high-burning rate catalysts [5], as catalysts in homogeneous catalysis [6], as building blocks in model systems for molecular wires [7,8,9,10,11,12,13,14]. Or as active ingredients in anticancer therapies [15,16]. As a result, charge transfer interactions with ferrocenyl-functionalized -conjugated hydrocarbons, such as arenes or five- and six-membered heterocycles, have been investigated [17,18,19,20,21].
Multi-ferrocenyl compounds, particularly biferrocene complexes in which two ferrocenyl units are connected by separate covalent units, can easily form mixed-valent (MV) Fe(II)-Fe(III) species by chemical or electrochemical oxidation [22,23,24]. As electronic wires, these compounds have received attention lately [25,26]. In specific, Electrochemical studies of electronic intramolecular communication among covalently coupled redox units have made extensive use of such substances.
On the other hand, convenient and efficient synthetic methodologies of fused thiophenes has attracted considerable attention, due to the importance of such compounds as scaffolds in the world of pharmaceuticals and functional materials [27,28,29,30,31]. Fused thiophenes can be accessed by a variety of reactions [32,33,34,35,36] including the Rosenmund−von Braun reaction [37], intramolecular Friedel−Crafts acylations [38] and Suzuki−Miyaura carbon, carbon cross-couplings [39].
In order to continue our research on ferrocenyl-substituted compounds [40,41,42,43,44,45,46,47,48,49,50,51,52], this article reports on the reaction chemistry and chemical and physical properties of the ferrocenylmethylester 3,4-[Fe(η5-C5H5)(η5-C5H4CH2OC(O)]2-cC4H2S (3). The formation of FcCH2OH (2) along with thieno [3,4-c]furan-1,3-dione (7) from 3 is discussed.

2. Results and Discussion

Treatment of diacid dichloride 3,4-(ClC(O))2-cC4H2S (1) with two equiv. of FcCH2OLi (2-Li) at −78 °C in diethyl ether gave 3,4-(FcCH2OC(O))2-cC4H2S (3) in excellent yield (Scheme 1, Experimental).
The newly synthesized ferrocenyl-thiophene 3 did not require elaborative purification procedures. After diethyl ether filtration of the reaction mixture through a pad of Celite, followed by removal of all volatiles, the obtained residue was precipitated from a chloroform/hexane mixture of ratio 3:1 (v/v).
Compound 3 was identified by IR and 1H and 13C{1H} NMR spectroscopies, elemental analysis, high-resolution mass spectrometry, and electrochemistry.
The IR spectrum of a freshly purified sample of 3, for example, shows a characteristic ν(CO) stretching vibration at 1706 cm−1, typical for carbonyl functionalities of the C(O)OCH2Fc units [45,49,53].
The 1H NMR spectrum of 3 is consistent with its molecular structure, showing resonance signals with the expected coupling patterns for the ferrocenyl groups and the heterocyclic moiety (Experimental) [40,41,42,44,48,49]. The ferrocenyl’ C5H5 protons of 3 give rise to a singlet at 4.17 ppm, while the ones of the C5H4 rings appear as two pseudo-triplets at 4.32 and 4.20 ppm with JHH = 1.7 Hz, appearing in a similar range as characteristic for the analogous 2,5-substituted isomer 2,5-[(Fe(η5-C5H5)(η5-C5H4CH2OC(O)]2-cC4H2S (5). [49,54] The cC5H2S and the CH2 protons are observed as singlets at 7.79 and 5.04 ppm, respectively.
In the 13C{1H} NMR spectrum of 3 the signal of the carbonyl carbon atom of the C(O)OCH2Fc entity, observed at 163.0 ppm, is the most representative [49]. The α and β carbon atoms of the thiophene moiety appear at 131 and 133 ppm, respectively. All other organic groups show the anticipated signals without any peculiarities [49].
The electrochemical investigations of 3 were carried out under an atmosphere of argon in dichloromethane solutions containing [NnBu4] [B(C6F5)4] (0.1 M) as supporting electrolyte at 25 °C and were referenced against the potential of the FcH/FcH+ redox couple (Figure 1) [55].
From the cyclic voltammetry data, two individual reversible one-electron processes with ipc/ipa ratio close to unity are observed and the formal potentials (Figure 1, ΔE°′ = 69 mV, and 146 mV, respectively) are significantly anodic shifted in comparison to the ferrocene redox event (Cp2Fe/Cp2Fe+) reflecting the electron-withdrawing nature of the −OC(O)R substituents. However, the presence of a small redox splitting between the first and the second oxidation step may indicate a certain degree of electronic and electrostatic interactions between the ferrocene moieties through the 3,4-dicarboxilate thiophene bridges [56,57]. Such behavior were noticed in a previously made electrochemical analysis of aryl-functionalized ferrocenylmethylesters (2,5-[(Fe(η5-C5H5)(η5-C5H4CH2OC(O)]2-cC4H2S, (label as 5 with the corresponding literature)) [49]. In addition, in comparing, a difference in the electronic and the electrostatic interactions as a function to the relative position of the two ferrocenylmethylcarboxilates on the thiophene ring are noticed too and reflected as the redox potentials of 3 significantly anodically shifted.
In order to observe the effect of the different substituents on the electronic properties of 3 and 5 the calculated energies and electron densities of the frontier molecular orbitals were investigated. Figure 2 summarizes the calculated energies of the HOMO and LUMO orbitals, in particular, the HOMO-LUMO energy gap values and the appropriate HOMO and LUMO contour plots of 3 and 5.
The DFT results of 3 and 5 reveal that the lowest unoccupied molecular orbitals are localized on the heterocycle fragment with no contribution fromf the ferrocenyls. On the other hand, for 3 it is found that the HOMOs are localized on one ferrocenyl fragment, while for 8 they are localized on both ferrocenyls. The energy levels of the HOMO orbitals of both compounds are clearly close to each other, while the calculated LUMO orbitals of 3 show with 1 eV higher energies than that of 8. The LUMO orbital energy increases significantly as a function of the relative positions of the two ferrocenylmethyls on the thiophene ring in 3 and 5, indicating that changing the position of the fragments on the thiophene ring reduces electron density delocalization within the thiophene ring in the LUMO. A similar tendency was observed for the two FcCH2 units on the six membered aromatic ring [(FcCH2OC(O))2-C6H4], by switching from ortho to para positions [49].
In attempts to grow single crystals of 3 in chloroform: hexane (ration 1:4 v/v) solvent mixtures under air at −18 °C, it was found that 3 further reacts with moisture and forms hydroxymethyl ferrocene (2) and 3,4-thiophenedicarboxylic anhydride (4) (Scheme 2). The structures of compounds 2 and 4 were identified based on their spectroscopy data and by comparison of their data with literature sources [37,58].
The molecular structure of 4 in the solid state was determined by single crystal X-ray structure analysis. Pale yellow plates were obtained by cooling a chloroform/hexane mixture of ratio 1:4 (v/v) containing 4 to −18 °C. Table S1 (See the ESI) summarizes the compound’s crystallographic and refining data. Figure 3 depicts the molecular structure of 7, with selected bond distances (Å), angles, and torsion angles (o) are listed in the caption.
Up to now, the crystal structures of fused thiophene compounds have been reported rarely. The title compound, thieno [3,4-c]furan-1,3-dione, with the molecule formula of C6H2O3S, crystallizes in the tetragonal space group P 42/n. All of the atoms are nearly co-planar. The thiophene ring displays C–C single bond lengths of 1.407(3) Å, slightly different to those in the furan ring (1.465(3) and 1.465(3) Å). The C=C double bond lengths are 1.356(3)/1.361(3) Å. The C–O bond distances can clearly be distinguished between carbonyl C=O (1.191(3) Å and 1.195(3) Å) and ether C–O (1.401(2) Å and 1.405(2) Å). All bond lengths and angles of the fused thiophenes compound are normal and comparable with its analogues [14,40]. The molecular association pattern is dominated by S···O and O···O interactions found within the sum of van der Waals radii (O/S = 1.52, 1.8 Å, ∑ = 3.32 Å; O/O = 1.52 Å, ∑ = 3.02 Å). Most prominent is a square arrangement of four molecules of based on short O···O distances between carbonyl oxygens O2 and O3 (Figure 4). Notably, the square interaction pattern is associated with short O···C interactions based on O2 and the adjacent anhydride ring in a T-shaped π fashion (omitted in Figure 4). The latter displays a very short distance between O2 and the centroid (Ct) of the heterocycle of 2.8292(4) Å (C2–O2···Ct = 140.95(1)°), indicating a strong donor-acceptor interaction. Further short O···C contacts appear between the C1=O1 functionalities of two adjacent molecules, with the electron-rich oxygen being positioned over the carbonyl carbon (O1···C1 = 3.1802(4) Å).
Via S1 and the O1-labled carbonyl oxygen the cubic structure interacts further via O1···S1 contacts that are present at both sites of the molecules, forming a band-type structure (Figure 5). Based on the square arrangement these bands form planes parallel to (110) and (1–10) hence intersecting perpendicularly. Furthermore, weak intermolecular C–H···O hydrogen bonding stabilizes the crystal packing of 7 (Table 1).
In total, a three-dimensional network is formed based on short and very strong interaction patterns. However, cavities remain (Figure 6, top), which are filled by an individual second network that interpenetrates the first one highlighted in black and blue in Figure 6. Weaker dispersion interactions between the π-orbitals of the C=O functionalities of adjacent molecules (O/C = 3.18 Å; ∑o,x = 3.22 Å) connect both 3D-networks (Figure 7).
To accomplish the description of the supramolecular connectivity in the crystal structure of 1, a Hirshfeld surface analysis was realized. Maps of the Hirshfeld surface, shape index and curvedness were generated based on the crystallographic information file (CIF) using the CrystalExplorer 3.1 program [59,60]. Hirshfeld surfaces enable the visualization of intermolecular interactions and indicate the relative strength of the interactions by different colors and color intensity. In the dnormal map (Figure 8), the vivid red spots are due to short normalized O···H/H···O, C···O/H···C, O···S/S···O, O···O; C···C, H···H, S···S, and C···H interactions. The white areas depicted at either side of the molecular structures in the Hirshfeld surface represent the aromatic rings and are footmarks of pep interactions [61,62]. On the shape-index surface of compound 4, convex blue regions represent hydrogen-donor groups and concave red regions represent hydrogen-acceptor groups. Figure 8 illustrates that the thiophene unit behaves simultaneously as donor and acceptor group. Meanwhile, the carbonyl substituents are acceptors only. Two-dimensional fingerprint plots quantify the contributions of each type of non-covalent interactions on the Hirshfeld surface map [63,64]. Analysis of the 2D fingerprint plots (Figure 9) reveals that the major contribution corresponding to 39.8% of the surface is due to O···H/H···O contacts (Figure 9f), indicating that aside from hydrogen bonding interactions van der Waals contacts are relevant for the molecular packing in the crystal structure. C···O/H···C interactions contribute 18.2% (Figure 8g), the O···S/S···O interactions 9.9% (Figure 9h), while O···O contributes 6.2% (Figure 9c). The remaining contacts, i.e., C···C, H···H, S···S and C···H, respectively, to the crystal structure stabilization (Figure 9a,b,d,e).
The enrichment ratios E, the ratio between the actual contacts proportion in the crystal and random contacts (theoretical proportion), were computed with MoProViewer program [65]. Values of E > 1 indicate that the pair of elements involved have a high propensity to form contacts in the crystal structure, while an E < 1 value indicates that the propensity would be low [66]. The contributions to the surfaces (taking into account the inner and outer surfaces) in 4 and the corresponding enrichment ratios are presented in Table 2. The enrichment ratios of 4 show that the O···H contacts (EOH = 2.18) is the most favoured contact in the crystal packing followed by the S···S (ESS = 2.04), O···C (EOC = 1.21) and C···C contacts (ECC = 1.16), respectively. The O···H contacts cover 24.98% of the total Hirshfeld surface of 4, while the surface contacts of O···C covers 22.97%, illustrating the importance of these relatively weak interactions in the molecular packing of 4.
Interaction energies were computed using CrystalExplorer to evaluate the role of the various intermolecular interactions in stabilizing the molecular packing of 4 [67]. The interaction energies between molecular pairs were calculated for a cluster of 3.8 Å around the central molecule. The molecular pair interaction energies are expressed in terms of total energy (E_tot), electrostatic energy (E_ele), polarization energy (E_pol), dispersion energy (E_dis), and repulsion energy (E_rep). The values of these energies for 4 are listed in Table 3. The highest stabilized molecular pairs in 4 (E = −32.5 kJ/mol) is related to the three molecules linked by the O···O, O···H and O···C short contacts (all within the sum of van der Waals radii), where the main stabilizing energy is due to the E_ele contribution followed by E_dis. The second highest stabilized molecular pairs in 4 (E = −16.1 kJ/mol) are related to the three molecules linked by the S···O, O···H and O···C short contacts (all within the sum of van der Waals radii). The main stabilizing energy of these molecules is also due to the E_ele contribution followed by E_dis.

3. Conclusions

The synthesis of 3,4-((FcCH2OC(O))2-cC4H2S (3) by treatment of FcCH2OLi with 3,4-(ClC(O))2-cC4H2S (2) is described. Electrochemical measurements on 3 showed that the substitution pattern of the ester on the aryl ring and the electron-withdrawing effect of the acyl groups influences the electrochemical shift of the formal potential. The respective aryl system possesses a significantly higher Fc/Fc+ vs. Cp2Fe/Cp2Fe+ redox potential as observed for the more electron-rich ferrocenemethanol [68,69]. DFT calculations show different degrees of HOMO-LUMO energy gaps when comparing 3 with 5 due to changing the LUMO energy depending on the positions of the carboxylic ester substituents on the thiophene rings. Compound 3 decomposes in solution with moisture to form 1-hydroxymethyl ferrocene (2) and thieno [3,4-c]furan-1,3-dione (4) which was characterized by single X-ray structure analysis.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/inorganics10070096/s1, Table S1: Crystallographic data and refinement details for 4.

Author Contributions

Investigation A.G.; Conceptualization, Writing–original draft, D.T.; Conceptualization, Single Crystal data collection and analysis, M.K. And T.R.; Formal analysis, K.A.K., W.H., H.A. and Z.I.; Funding acquisition, H.L. All authors have read and agreed to the published version of the manuscript.

Funding

We are grateful to the University of Jordan and Al Ahliyya Amman University for financial support.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Acknowledgments

The authors greatly appreciate and acknowledge of financial support received from the University of Jordan and Al Ahliyya Amman University.

Conflicts of Interest

The authors declare no conflict of interest.

Supporting Data

Crystallographic data (excluding structure factors) have been deposited with the Cambridge Crystallographic Data Centre as supplementary publication CCDC-2099570 for 4. Copies of the data can be obtained free of charge on application to CCDC, 12 Union Road, Cambridge CB2 1EZ, UK [E-mail: deposit@ccdc.cam.ac.uk].

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Inorganics 10 00096 sch001
Scheme 1. Synthesis of 3. (i) 1 (1 equiv), 2-Li (2 equiv), diethyl ether, −78 °C, 18 h. Yield is based on 1. 2-Li was prepared in situ by an equimolar reaction of 2 with MeLi in diethyl ether [45,49].
Scheme 1. Synthesis of 3. (i) 1 (1 equiv), 2-Li (2 equiv), diethyl ether, −78 °C, 18 h. Yield is based on 1. 2-Li was prepared in situ by an equimolar reaction of 2 with MeLi in diethyl ether [45,49].
Inorganics 10 00096 sch001
Inorganics 10 00096 g001
Figure 1. Cyclic voltammogram (bottom) and square-wave voltammogram (top) of 3 in anhydrous dichloromethane solutions (1.0 mM) at 25 °C, supporting electrolyte [NnBu4] [B(C6F5)4] (0.1 M), 100 mV/s.
Figure 1. Cyclic voltammogram (bottom) and square-wave voltammogram (top) of 3 in anhydrous dichloromethane solutions (1.0 mM) at 25 °C, supporting electrolyte [NnBu4] [B(C6F5)4] (0.1 M), 100 mV/s.
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Inorganics 10 00096 g002
Figure 2. Frontier orbitals (HOMO and LUMO) for compounds 3 (left) and 5 (right), calculated at the B3LYP/6-31+G(d,p) and LANL2DZ level in dichloromethane, with isosurface 0.04. The HOMO-LUMO gap for both compounds is indicated in eV.
Figure 2. Frontier orbitals (HOMO and LUMO) for compounds 3 (left) and 5 (right), calculated at the B3LYP/6-31+G(d,p) and LANL2DZ level in dichloromethane, with isosurface 0.04. The HOMO-LUMO gap for both compounds is indicated in eV.
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Inorganics 10 00096 sch002
Scheme 2. Formation of thieno [3,4-c]furan-1,3-dione (7) by the H2O-mediated cyclization of 3 under atmospheric conditions to give 2 and 4.
Scheme 2. Formation of thieno [3,4-c]furan-1,3-dione (7) by the H2O-mediated cyclization of 3 under atmospheric conditions to give 2 and 4.
Inorganics 10 00096 sch002
Inorganics 10 00096 g003
Figure 3. ORTEP (50% probability level) of the molecular structure of 4 with the atom-numbering scheme. Selected bond distances (Å), angles (o) and torsion angles (o): S1–C5 = 1.722(2), S1–C6 = 1.713(2), O1–C1 = 1.195(3), O3–C2 = 1.191(3), O2–C2 = 1.405(2), O3–C1 = 1.401(2), C1–C3 = 1.465(3), C2–C4 = 1.465(3), C3–C4 = 1.407(3), C4–C6 = 1.356(3), C3–C5 = 1.361(3); O1–C1–O3 = 119.68(18), O3–C1–C3 = 106.60(16), C2–O3–C1 = 110.65(15), C6–S1–C5 = 93.75(10), C1–C3–C4–C6 = −178.53(16), O1–C1–O3–C2 = 178.62(19), C4–C6–S1–C5 = −0.25(15).
Figure 3. ORTEP (50% probability level) of the molecular structure of 4 with the atom-numbering scheme. Selected bond distances (Å), angles (o) and torsion angles (o): S1–C5 = 1.722(2), S1–C6 = 1.713(2), O1–C1 = 1.195(3), O3–C2 = 1.191(3), O2–C2 = 1.405(2), O3–C1 = 1.401(2), C1–C3 = 1.465(3), C2–C4 = 1.465(3), C3–C4 = 1.407(3), C4–C6 = 1.356(3), C3–C5 = 1.361(3); O1–C1–O3 = 119.68(18), O3–C1–C3 = 106.60(16), C2–O3–C1 = 110.65(15), C6–S1–C5 = 93.75(10), C1–C3–C4–C6 = −178.53(16), O1–C1–O3–C2 = 178.62(19), C4–C6–S1–C5 = −0.25(15).
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Inorganics 10 00096 g004
Figure 4. Intermolecular interactions within the sum of the van-der-Waals radii for compound 4, showing the central square pattern. Symmetry operation for generating equivalent atoms: (A) y, 1/2 − x, 3/2 − z; (B) 1/2 − x, 1/2 − y, z; (C) 1/2 − y, x, 3/2 − z.
Figure 4. Intermolecular interactions within the sum of the van-der-Waals radii for compound 4, showing the central square pattern. Symmetry operation for generating equivalent atoms: (A) y, 1/2 − x, 3/2 − z; (B) 1/2 − x, 1/2 − y, z; (C) 1/2 − y, x, 3/2 − z.
Inorganics 10 00096 g004
Inorganics 10 00096 g005
Figure 5. Intermolecular interaction in the packing of 7, highlighting the O1···S1 pattern parallel to (1–10). Symmetry operation for generating equivalent atoms: (D) −1/2 + x, −1/2 + y, −z; (E) x + 1, y − 1, z.
Figure 5. Intermolecular interaction in the packing of 7, highlighting the O1···S1 pattern parallel to (1–10). Symmetry operation for generating equivalent atoms: (D) −1/2 + x, −1/2 + y, −z; (E) x + 1, y − 1, z.
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Inorganics 10 00096 g006
Figure 6. Combination of the interaction pattern of 4, described in Figure 4 and Figure 5 (top), and two interpenetrating networks of strong O···S interactions that complete the packing in the solid state of 4.
Figure 6. Combination of the interaction pattern of 4, described in Figure 4 and Figure 5 (top), and two interpenetrating networks of strong O···S interactions that complete the packing in the solid state of 4.
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Inorganics 10 00096 g007
Figure 7. Electrostatic C···O interactions of 7, that occur between both interpenetrating networks, shown in Figure 6.
Figure 7. Electrostatic C···O interactions of 7, that occur between both interpenetrating networks, shown in Figure 6.
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Inorganics 10 00096 g008
Figure 8. Hirshfeld surface of compound 4.
Figure 8. Hirshfeld surface of compound 4.
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Inorganics 10 00096 g009
Figure 9. Hirshfeld fingerprint plots of compound 4 for (a) C···C, (b) H···H interactions, (c) O···O, (d) S···S, (e) C–H/H–C, (f) O–H/H–O, (g) C···O/O···C and (h) O···S/S···O interactions.
Figure 9. Hirshfeld fingerprint plots of compound 4 for (a) C···C, (b) H···H interactions, (c) O···O, (d) S···S, (e) C–H/H–C, (f) O–H/H–O, (g) C···O/O···C and (h) O···S/S···O interactions.
Inorganics 10 00096 g009
Table 1. Hydrogen bond geometry (Å, °) for compound 7.
Table 1. Hydrogen bond geometry (Å, °) for compound 7.
D–H···AD–HH···AD···AD–H···A
C6–H7···O2i0.932.543.2708(4)136
C6–H7···O1ii0.932.573.1211(4)118
Symmetry codes: (i) −1 + y, 1/2 − x, 1/2 − z (ii) −1/2 + x, −1/2 + y, −z.
Table 2. Hirshfeld contact surfaces and enhancement ratios (E) for 4.
Table 2. Hirshfeld contact surfaces and enhancement ratios (E) for 4.
AtomsHCOS
Surface interior (%)17.5330.6731.4120.39
Surface exterior (%)17.8628.1633.2220.76
Actual contacts merged (%)
H0.68---
C6.3710.00--
O24.9822.972.50-
S2.689.4811.698.65
Equiprobable contacts merged (%)
H3.13---
C10.418.64--
O11.4319.0310.43-
S7.2812.1113.304.23
Enrichment reciprocal contacts merged (%)
H0.22---
C0.611.16--
O2.181.210.24-
S0.370.780.882.04
Table 3. Selected interaction energies (kJ/mol) (with E_tot > −50.0 kJ/mol) for 4.
Table 3. Selected interaction energies (kJ/mol) (with E_tot > −50.0 kJ/mol) for 4.
ContactsSymmetry OperationE_eleE_polE_disE_repE_tot
O···O, O···H, and O···Cy, −x + 1/2, −z + 1/2−25.7−5.0−17.622.2−32.5
S···O, O···H, and O···Cx + 1/2, y + 1/2, −z−13.4−2.8−6.69.5−16.1
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Ghazzy, A.; Taher, D.; Korb, M.; Al Khalyfeh, K.; Helal, W.; Amarne, H.; Rüffer, T.; Ishtaiwi, Z.; Lang, H. Rearrangement of Diferrocenyl 3,4-Thiophene Dicarboxylate. Inorganics 2022, 10, 96. https://doi.org/10.3390/inorganics10070096

AMA Style

Ghazzy A, Taher D, Korb M, Al Khalyfeh K, Helal W, Amarne H, Rüffer T, Ishtaiwi Z, Lang H. Rearrangement of Diferrocenyl 3,4-Thiophene Dicarboxylate. Inorganics. 2022; 10(7):96. https://doi.org/10.3390/inorganics10070096

Chicago/Turabian Style

Ghazzy, Asma, Deeb Taher, Marcus Korb, Khaled Al Khalyfeh, Wissam Helal, Hazem Amarne, Tobias Rüffer, Zakariyya Ishtaiwi, and Heinrich Lang. 2022. "Rearrangement of Diferrocenyl 3,4-Thiophene Dicarboxylate" Inorganics 10, no. 7: 96. https://doi.org/10.3390/inorganics10070096

APA Style

Ghazzy, A., Taher, D., Korb, M., Al Khalyfeh, K., Helal, W., Amarne, H., Rüffer, T., Ishtaiwi, Z., & Lang, H. (2022). Rearrangement of Diferrocenyl 3,4-Thiophene Dicarboxylate. Inorganics, 10(7), 96. https://doi.org/10.3390/inorganics10070096

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