1
|
Junk PC, Werner D, Rad NE, Guo Z, Deacon GB. New Interventions by silicone grease in synthesis. Z Anorg Allg Chem 2022. [DOI: 10.1002/zaac.202200222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Peter Courtney Junk
- James Cook University Dept. of Chemistry James Cook Drive 4811 Townsville AUSTRALIA
| | - Daniel Werner
- School of Chemistry, Monash University, Clayton 3800, Australia AUSTRALIA
| | - Nazli E. Rad
- College of Science & Engineering, James Cook University, Townsville 4811, Qld, Australia AUSTRALIA
| | - Zhifang Guo
- College of Science & Engineering, James Cook University, Townsville 4811, Qld, Australia AUSTRALIA
| | - Glen B. Deacon
- School of Chemistry, Monash University, Clayton 3800, Australia AUSTRALIA
| |
Collapse
|
2
|
Buchner MR, Thomas-Hargreaves LR. s-Block chemistry in weakly coordinating solvents. Dalton Trans 2021; 50:16916-16922. [PMID: 34738606 DOI: 10.1039/d1dt03443j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Alkaline earth metal catalysis has been a growing field in recent years. To enhance reactivity and to understand the metal-substrate interactions in more detail, reactions are increasingly carried out in weakly coordinating solvents. This article gives an overview over the two main approaches to facilitate this, which are either through the employment of highly dipolar haloaryls as solvents, or by increasing the solubility of the ligand systems. The resulting coordination modes and reactivities are presented together with the synthetic strategies. Additionally, the latest results of group 1 complex chemistry in aliphatic solvents are illustrated and future challenges are highlighted.
Collapse
Affiliation(s)
- Magnus R Buchner
- Anorganische Chemie, Nachwuchsgruppe Hauptgruppenmetallchemie, Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany.
| | - Lewis R Thomas-Hargreaves
- Anorganische Chemie, Nachwuchsgruppe Hauptgruppenmetallchemie, Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany.
| |
Collapse
|
3
|
Dankert F, Hänisch C. Siloxane Coordination Revisited: Si−O Bond Character, Reactivity and Magnificent Molecular Shapes. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100275] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Fabian Dankert
- Leibniz-Institut für Katalyse e. V. (LIKAT Rostock) Albert-Einstein-Str. 29a 18059 Rostock Germany
| | - Carsten Hänisch
- Fachbereich Chemie und Wissenschaftliches Zentrum für Materialwissenschaften (WZMW) Philipps-Universität Marburg Hans-Meerwein-Straße 4 35032 Marburg Germany
| |
Collapse
|
4
|
Chen H, Pang Z, Qiao Q, Xia Y, Wei Y, Gao Y, Zhang J, Qian S. Puerarin-Na Chelate Hydrate Simultaneously Improves Dissolution and Mechanical Behavior. Mol Pharm 2021; 18:2507-2520. [PMID: 34142830 DOI: 10.1021/acs.molpharmaceut.1c00005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Puerarin monohydrate (PUEM), as the commercial solid form of the natural anti-hypertension drug puerarin (PUE), has low solubility, poor flowability, and mechanical properties. In this study, a novel solid form as PUE-Na chelate hydrate was prepared by a reactive crystallization method. Crystal structure analysis demonstrated that PUE-Na contains PUE-, Na+, and water in a molar ratio of 1:1:7. It crystallizes in the monoclinic space group P21, and Na+ is linked with PUE- and four water molecules through Na+ ← O coordination bonds. Another three crystal water molecules occupy channels along the crystallographic b-axis. Observing along the b-axis, the crystal structure features a distinct tubular helix and a DNA-like twisted helix. The complexation between Na+ and PUE- in aqueous solution was confirmed by the Na+ selective electrode, indicating that PUE-Na chelate hydrate belongs to a type of chelate rather than organic metal salt. Compared with PUEM, PUE-Na exhibited a superior dissolution rate (i.e., ∼38-fold increase in water) owing to its lower solvation free energy and clear-enriched exposed polar groups. Moreover, PUE-Na enhanced the tabletability and flowability of PUEM, attributing to its better elastoplastic deformation and lower-friction crystal habit. The unique PUE-Na chelate hydrate with significantly enhanced pharmaceutical properties is a very promising candidate for future product development of PUE.
Collapse
Affiliation(s)
- Hui Chen
- School of Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China
| | - Zunting Pang
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China
| | - Qiyang Qiao
- School of Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China
| | - Yanming Xia
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China
| | - Yuanfeng Wei
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China
| | - Yuan Gao
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China
| | - Jianjun Zhang
- School of Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China
| | - Shuai Qian
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China
| |
Collapse
|
5
|
Dankert F, Richter R, Weigend F, Xie X, Balmer M, Hänisch C. Aufbau anorganischer Kronenether durch s‐Block‐Metall‐templatgesteuerte Si‐O‐Bindungsaktivierung. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202014822] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Fabian Dankert
- Fachbereich Chemie Philipps-Universität Marburg Hans-Meerwein-Straße 4 35032 Marburg Deutschland
| | - Roman‐Malte Richter
- Fachbereich Chemie Philipps-Universität Marburg Hans-Meerwein-Straße 4 35032 Marburg Deutschland
| | - Florian Weigend
- Fachbereich Chemie Philipps-Universität Marburg Hans-Meerwein-Straße 4 35032 Marburg Deutschland
| | - Xiulan Xie
- Fachbereich Chemie Philipps-Universität Marburg Hans-Meerwein-Straße 4 35032 Marburg Deutschland
| | - Markus Balmer
- Fachbereich Chemie Philipps-Universität Marburg Hans-Meerwein-Straße 4 35032 Marburg Deutschland
| | - Carsten Hänisch
- Fachbereich Chemie Philipps-Universität Marburg Hans-Meerwein-Straße 4 35032 Marburg Deutschland
| |
Collapse
|
6
|
Dankert F, Richter R, Weigend F, Xie X, Balmer M, von Hänisch C. Construction of Inorganic Crown Ethers by s-Block-Metal-Templated Si-O Bond Activation. Angew Chem Int Ed Engl 2021; 60:10393-10401. [PMID: 33591587 PMCID: PMC8252370 DOI: 10.1002/anie.202014822] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 02/01/2021] [Indexed: 11/07/2022]
Abstract
We herein report the synthesis, structures, coordination ability, and mechanism of formation of silicon analogs of crown ethers. An oligomerization of 2 D2 (I) (2 Dn ,=(Me4 Si2 O)n ) was achieved by the reaction with GaI3 and MIx (M=Li, Na, Mg, Ca, Sr). In these reactions the metal cations serve as template and the anions (I- /[GaI4 ]- ) are required as nucleophiles. In case of MIx =LiI, [Li(2 D3 )GaI4 ] (1) is formed. In case of MIx =NaI, MgI2 , CaI2 , and SrI2 the compounds [M(2 D4 )(GaI4 )x ] (M=Mg2+ (3), Ca2+ (4), Sr2+ (5) are obtained. Furthermore the proton complex [H(2 D3 )][Ga2 I7 ] (6) was isolated and structurally characterized. All complexes were characterized by means of multinuclear NMR spectroscopy, DOSY experiments and, except for compound 3, also by single crystal X-ray diffraction. Quantum chemical calculations were carried out to compare the affinity of M+ to 2 Dn and other ligands and to shed light on the formation of larger rings from smaller ones.
Collapse
Affiliation(s)
- Fabian Dankert
- Fachbereich ChemiePhilipps-Universität MarburgHans-Meerwein-Strasse 435032MarburgGermany
| | - Roman‐Malte Richter
- Fachbereich ChemiePhilipps-Universität MarburgHans-Meerwein-Strasse 435032MarburgGermany
| | - Florian Weigend
- Fachbereich ChemiePhilipps-Universität MarburgHans-Meerwein-Strasse 435032MarburgGermany
| | - Xiulan Xie
- Fachbereich ChemiePhilipps-Universität MarburgHans-Meerwein-Strasse 435032MarburgGermany
| | - Markus Balmer
- Fachbereich ChemiePhilipps-Universität MarburgHans-Meerwein-Strasse 435032MarburgGermany
| | - Carsten von Hänisch
- Fachbereich ChemiePhilipps-Universität MarburgHans-Meerwein-Strasse 435032MarburgGermany
| |
Collapse
|
7
|
Jost M, Richter RM, Balmer M, Peters B, Dankert F, von Hänisch C. Coordination polymers of alkali metal cyclosiloxazanides with one- and two-dimensional structures. Dalton Trans 2020; 49:5787-5790. [PMID: 32314766 DOI: 10.1039/d0dt01060j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction of O(Si2Me4Cl)2 with ammonia yielded the cyclic siloxazane O(Si2Me4)2NH (1), which was used as a precursor for the synthesis of siloxazanide-type alkali metal salts. The metalation of 1 with the strong bases BzA (A = Na, K, Rb, Cs and Bz = benzyl) results in different dimensional structures depending on the alkali metal ion used. These results give new insights into framework design with inorganic building blocks and the coordination ability of siloxanes.
Collapse
Affiliation(s)
- Maximilian Jost
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW), Philipps-Universität Marburg, Hans-Meerwein-Straße, 35043 Marburg, Germany.
| | | | | | | | | | | |
Collapse
|
8
|
Fromm KM. Chemistry of alkaline earth metals: It is not all ionic and definitely not boring! Coord Chem Rev 2020. [DOI: 10.1016/j.ccr.2020.213193] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
9
|
Dankert F, Deubner HL, Müller M, Buchner MR, Kraus F, von Hänisch C. C–F Bond Cleavage Reactions with Beryllium, Magnesium, Gallium, Hafnium, and Thorium Halides. Z Anorg Allg Chem 2020. [DOI: 10.1002/zaac.201900297] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Fabian Dankert
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW) Philipps‐Universität Marburg Hans‐Meerwein Str. 4 35032 Marburg Germany
| | - H. Lars Deubner
- Fachbereich Chemie: Anorganische Chemie Fluorchemie Philipps‐Universität Marburg Hans‐Meerwein Str. 4 35032 Marburg Germany
| | - Matthias Müller
- Fachbereich Chemie: Anorganische Chemie Nachwuchsgruppe Berylliumchemie Philipps‐Universität Marburg Hans‐Meerwein Str. 4 35032 Marburg Germany
| | - Magnus R. Buchner
- Fachbereich Chemie: Anorganische Chemie Nachwuchsgruppe Berylliumchemie Philipps‐Universität Marburg Hans‐Meerwein Str. 4 35032 Marburg Germany
| | - Florian Kraus
- Fachbereich Chemie: Anorganische Chemie Fluorchemie Philipps‐Universität Marburg Hans‐Meerwein Str. 4 35032 Marburg Germany
| | - Carsten von Hänisch
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW) Philipps‐Universität Marburg Hans‐Meerwein Str. 4 35032 Marburg Germany
| |
Collapse
|
10
|
Dankert F, Erlemeier L, Ritter C, von Hänisch C. On the molecular architectures of siloxane coordination compounds: (re-)investigating the coordination of the cyclodimethylsiloxanes Dn(n= 5–8) towards alkali metal ions. Inorg Chem Front 2020. [DOI: 10.1039/d0qi00109k] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Cyclodimethylsiloxanes have been used as complex ligands and silyl-ether bonding towards various cations is explored stepwise. Compounds with unprecedented coordination modes as well as novel molecular architectures are obtained and characterized.
Collapse
Affiliation(s)
- Fabian Dankert
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW)
- Philipps-Universität Marburg
- Marburg
- Germany
| | - Lukas Erlemeier
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW)
- Philipps-Universität Marburg
- Marburg
- Germany
| | - Christian Ritter
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW)
- Philipps-Universität Marburg
- Marburg
- Germany
| | - Carsten von Hänisch
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW)
- Philipps-Universität Marburg
- Marburg
- Germany
| |
Collapse
|
11
|
Dankert F, Donsbach C, Rienmüller J, Richter RM, von Hänisch C. Alkaline Earth Metal Template (Cross-)Coupling Reactions with Hybrid Disila-Crown Ether Analogues. Chemistry 2019; 25:15934-15943. [PMID: 31596978 PMCID: PMC6916185 DOI: 10.1002/chem.201904209] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Indexed: 11/12/2022]
Abstract
Alkaline earth metal iodides were used as templates for the synthesis of novel silicon-based ligands. Siloxane moieties were (cross-)coupled and ion-specific, silicon-rich crown ether analogues were obtained. The reaction of 1,2,7,8-tetrasila[12]crown-4 (I) and 1,2-disila[9]crown-3 (II) with MgI2 yielded exclusively [Mg(1,2,7,8-tetrasila[12]crown-4)I2 ] (1). The larger Ca2+ ion was then employed for cross-coupling of I and II and yielded the complex [Ca(1,2,7,8-tetrasila[15]crown-5)I2 ] (2). Cross-coupling of I and 1,2,4,5-tetrasila[9]crown-3 (III) with SrI2 enables the synthesis of the silicon-dominant 1,2,4,5,10,11-hexasila[15]crown-5 ether complex of SrI2 (3). Further, the compounds [Sr(1,2,10,11-tetrasila[18]crown-6)I2 ] (4), [Sr(1,2,13,14-tetrasila[24]crown-8)I2 ] (5), and [Sr(1,2,13,14-tetrasila-dibenzo[24]crown-8)I2 ] (6) were obtained by coupling I, 1,2-disila[12]crown-4 (IV) or 1,2-disila-benzo[12]crown-4 (V), respectively. Using various anions, the (cross-)coupled ligands were also observed in an X-ray structure within the mentioned complexes. These template-assisted (cross-)couplings of various ligands are the first of their kind and a novel method to obtain macrocycles and/or their metal complexes to be established. Further, the Si-O bond activations presented herein might be of importance for silane or even organic functionalization.
Collapse
Affiliation(s)
- Fabian Dankert
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW)Philipps-Universität Marburg35032MarburgGermany
| | - Carsten Donsbach
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW)Philipps-Universität Marburg35032MarburgGermany
| | - Julia Rienmüller
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW)Philipps-Universität Marburg35032MarburgGermany
| | - Roman M. Richter
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW)Philipps-Universität Marburg35032MarburgGermany
| | - Carsten von Hänisch
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW)Philipps-Universität Marburg35032MarburgGermany
| |
Collapse
|
12
|
Dankert F, Weigend F, von Hänisch C. Not Non-Coordinating at All: Coordination Compounds of the Cyclodimethylsiloxanes D n (D = Me 2SiO; n = 6, 7) and Group 2 Metal Cations. Inorg Chem 2019; 58:15417-15422. [PMID: 31661251 DOI: 10.1021/acs.inorgchem.9b02519] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We present the coordination chemistry of the cyclodimethylsiloxanes D6 and D7 toward alkaline earth metal salts. The coordination chemistry of these macrocycles toward alkaline earth metals has been unprecedented to date, and we could show that these ligands coordinate better than previously thought. Direct reaction of alkaline earth metal salts with these ligands yields stable complexes even with a relatively strongly coordinating iodide anion. A handful of counterintuitive coordination compounds could be characterized by single-crystal X-ray diffraction analysis. Quantum chemical calculations of suited Born-Haber cycles showed that these complexes are indeed stable, for Mg2+ and Ca2+ even with iodide employed as the anion and for Sr2+ and Ba2+ in the presence of GaI3.
Collapse
Affiliation(s)
- Fabian Dankert
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW) , Philipps-Universität Marburg , 35032 Marburg , Germany
| | - Florian Weigend
- Institut für Nanotechnologie , Karlsruher Institut für Technologie , Hermann-von-Helmholtz-Platz 1 , 76344 Leopoldshafen-Eggenstein , Germany
| | - Carsten von Hänisch
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW) , Philipps-Universität Marburg , 35032 Marburg , Germany
| |
Collapse
|
13
|
Finelli A, Hérault N, Crochet A, Fromm KM. Compartmentalization of Alkaline-Earth Metals in Salen-Type Cu- and Ni-Complexes in Solution and in the Solid State. ACS OMEGA 2019; 4:10231-10242. [PMID: 31460115 PMCID: PMC6648824 DOI: 10.1021/acsomega.9b00365] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 04/25/2019] [Indexed: 06/10/2023]
Abstract
The precise arrangement of metal ions in type and number by a ligand represents an important challenge in biology as well as in materials science. The preorganization of different metal ions such as alkaline-earth and transition-metal ions is of particular interest for the design of catalysts or precursors of oxides. This study is based on a Ω-shaped salen-derived ligand comprising N2O2 and O2O2 coordination sites. The selective binding of Cu(II) and Ni(II) and alkaline-earth-metal ions is influenced by many factors such as the size of the cation, the solvent, or the counterion. UV-vis and 1H NMR titrations and single-crystal X-ray structures reveal that the obtained complexes tend to adopt different structures in solution compared to the solid state. Mainly discrete motifs with a stoichiometry 1:1 (LM1 to alkaline-earth-metal ions) have been shown to form in the solid state, whereas in solution, the 2:1 complexes are predominant.
Collapse
Affiliation(s)
- Alba Finelli
- Department
of Chemistry and FriMat, Department of Chemistry, University
of Fribourg, Ch. du Musée 9, 1700 Fribourg, Switzerland
| | - Nelly Hérault
- Department
of Chemistry and FriMat, Department of Chemistry, University
of Fribourg, Ch. du Musée 9, 1700 Fribourg, Switzerland
| | - Aurélien Crochet
- Department
of Chemistry and FriMat, Department of Chemistry, University
of Fribourg, Ch. du Musée 9, 1700 Fribourg, Switzerland
| | - Katharina M. Fromm
- Department
of Chemistry and FriMat, Department of Chemistry, University
of Fribourg, Ch. du Musée 9, 1700 Fribourg, Switzerland
| |
Collapse
|
14
|
Dankert F, von Hänisch C. Insights into the Coordination Ability of Siloxanes Employing Partially Silicon Based Crown Ethers: A Comparative Analysis of s-Block Metal Complexes. Inorg Chem 2019; 58:3518-3526. [DOI: 10.1021/acs.inorgchem.9b00086] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Fabian Dankert
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW), Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35043 Marburg, Germany
| | - Carsten von Hänisch
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW), Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35043 Marburg, Germany
| |
Collapse
|
15
|
Fugel M, Hesse MF, Pal R, Beckmann J, Jayatilaka D, Turner MJ, Karton A, Bultinck P, Chandler GS, Grabowsky S. Covalency and Ionicity Do Not Oppose Each Other-Relationship Between Si-O Bond Character and Basicity of Siloxanes. Chemistry 2018; 24:15275-15286. [PMID: 29999553 DOI: 10.1002/chem.201802197] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/11/2018] [Indexed: 11/07/2022]
Abstract
Covalency and ionicity are orthogonal rather than antipodal concepts. We demonstrate for the case of siloxane systems [R3 Si-(O-SiR2 )n -O-SiR3 ] that both covalency and ionicity of the Si-O bonds impact on the basicity of the Si-O-Si linkage. The relationship between the siloxane basicity and the Si-O bond character has been under debate since previous studies have presented conflicting explanations. It has been shown with natural bond orbital methods that increased hyperconjugative interactions of LP(O)→σ*(Si-R) type, that is, increased orbital overlap and hence covalency, are responsible for the low siloxane basicity at large Si-O-Si angles. On the other hand, increased ionicity towards larger Si-O-Si angles has been revealed with real-space bonding indicators. To resolve this ostensible contradiction, we perform a complementary bonding analysis, which combines orbital-space, real-space, and bond-index considerations. We analyze the isolated disiloxane molecule H3 SiOSiH3 with varying Si-O-Si angles, and n-membered cyclic siloxane systems Si2 H4 O(CH2 )n-3 . All methods from quite different realms show that both covalent and ionic interactions increase simultaneously towards larger Si-O-Si angles. In addition, we present highly accurate absolute hydrogen-bond interaction energies of the investigated siloxane molecules with water and silanol as donors. It is found that intermolecular hydrogen bonding is significant at small Si-O-Si angles and weakens as the Si-O-Si angle increases until no stable hydrogen-bond complexes are obtained beyond φSiOSi =168°, angles typically displayed by minerals or polymers. The maximum hydrogen-bond interaction energy, which is obtained at an angle of 105°, is 11.05 kJ mol-1 for the siloxane-water complex and 18.40 kJ mol-1 for the siloxane-silanol complex.
Collapse
Affiliation(s)
- Malte Fugel
- University of Bremen, Department 2-Chemistry/Biology, Institute of Inorganic Chemistry and Crystallography, Leobener Str. 3 and 7, 28359, Bremen, Germany
| | - Maxie F Hesse
- University of Bremen, Department 2-Chemistry/Biology, Institute of Inorganic Chemistry and Crystallography, Leobener Str. 3 and 7, 28359, Bremen, Germany
| | - Rumpa Pal
- University of Bremen, Department 2-Chemistry/Biology, Institute of Inorganic Chemistry and Crystallography, Leobener Str. 3 and 7, 28359, Bremen, Germany
| | - Jens Beckmann
- University of Bremen, Department 2-Chemistry/Biology, Institute of Inorganic Chemistry and Crystallography, Leobener Str. 3 and 7, 28359, Bremen, Germany
| | - Dylan Jayatilaka
- University of Western Australia, School of Molecular Sciences, 35 Stirling Highway, Perth, WA, 6009, Australia
| | - Michael J Turner
- University of Western Australia, School of Molecular Sciences, 35 Stirling Highway, Perth, WA, 6009, Australia
| | - Amir Karton
- University of Western Australia, School of Molecular Sciences, 35 Stirling Highway, Perth, WA, 6009, Australia
| | - Patrick Bultinck
- Ghent University, Department of Chemistry, Krijgslaan 281 (S3), 9000, Gent, Belgium
| | - Graham S Chandler
- University of Western Australia, School of Molecular Sciences, 35 Stirling Highway, Perth, WA, 6009, Australia
| | - Simon Grabowsky
- University of Bremen, Department 2-Chemistry/Biology, Institute of Inorganic Chemistry and Crystallography, Leobener Str. 3 and 7, 28359, Bremen, Germany
| |
Collapse
|
16
|
Dankert F, Heine J, Rienmüller J, von Hänisch C. Sila-polyethers as innocent crystallization reagents for heavy alkali metal compounds. CrystEngComm 2018. [DOI: 10.1039/c8ce01097h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sila-polyethers are used as innocent crystallization reagents for the formation of single crystals of different elusive rubidium and cesium salts.
Collapse
Affiliation(s)
- Fabian Dankert
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW)
- Philipps-Universität Marburg
- Marburg
- Germany
| | - Johanna Heine
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW)
- Philipps-Universität Marburg
- Marburg
- Germany
| | - Julia Rienmüller
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW)
- Philipps-Universität Marburg
- Marburg
- Germany
| | - Carsten von Hänisch
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW)
- Philipps-Universität Marburg
- Marburg
- Germany
| |
Collapse
|
17
|
Pahl J, Elsen H, Friedrich A, Harder S. Unsupported metal silyl ether coordination. Chem Commun (Camb) 2018; 54:7846-7849. [DOI: 10.1039/c8cc04517h] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Silyl ethers surrender to magnesium: the very weak Lewis base hexamethyldisiloxane is forced to ligate a “naked” cationic Mg species. Agostic interactions and van der Waals attraction contribute to stability.
Collapse
Affiliation(s)
- Jürgen Pahl
- Inorganic and Organometallic Chemistry
- University Erlangen-Nürnberg
- 91058 Erlangen
- Germany
| | - Holger Elsen
- Inorganic and Organometallic Chemistry
- University Erlangen-Nürnberg
- 91058 Erlangen
- Germany
| | - Alexander Friedrich
- Inorganic and Organometallic Chemistry
- University Erlangen-Nürnberg
- 91058 Erlangen
- Germany
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry
- University Erlangen-Nürnberg
- 91058 Erlangen
- Germany
| |
Collapse
|
18
|
Buchner MR, Müller M, Dankert F, Reuter K, von Hänisch C. The coordination behaviour and reactivity of partially silicon based crown ethers towards beryllium chloride. Dalton Trans 2018; 47:16393-16397. [DOI: 10.1039/c8dt03963a] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The reaction of partially silicon based crown ethers with BeCl2 yields eight-membered Be–O-heterocycles, which are annulated by two six-membered Be–O-cycles.
Collapse
Affiliation(s)
- Magnus R. Buchner
- Anorganische Chemie
- Nachwuchsgruppe Berylliumchemie
- Fachbereich Chemie
- Philipps-Universität Marburg
- 35032 Marburg
| | - Matthias Müller
- Anorganische Chemie
- Nachwuchsgruppe Berylliumchemie
- Fachbereich Chemie
- Philipps-Universität Marburg
- 35032 Marburg
| | - Fabian Dankert
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW)
- Philipps-Universität Marburg
- 35032 Marburg
- Germany
| | - Kirsten Reuter
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW)
- Philipps-Universität Marburg
- 35032 Marburg
- Germany
| | - Carsten von Hänisch
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW)
- Philipps-Universität Marburg
- 35032 Marburg
- Germany
| |
Collapse
|