Determination of the Structural Parameters of Heteronuclear (Phthalocyaninato)bis(crownphthalocyaninato)lanthanide(III) Triple-Deckers in Solution by Simultaneous Analysis of NMR and Single-Crystal X‑ray Data

Application of a general and convenient approach to the synthesis of heteronuclear crown-substituted triple-decker phthalocyaninates afforded two series of complexes containing one dia- and one paramagnetic Ln­(III) ion (for Y and almost the whole lanthanide family), [(15C5)₄Pc]­M*­[(15C5)₄Pc]­M­(Pc) (or [M*,M] for brevity sake), where (15C5) is 15-crown-5; (Pc^2–) is phthalocyaninato dianion; and M ≠ M* = Y, Nd, Eu, Tb, Dy, Ho, Er, Tm, Yb. This approach consists of using LaPc₂ as an efficient Pc^2– source. The solid-state structures of two complexes ([Tm*,Y] and [Yb*,Y]) were studied by single-crystal X-ray diffraction analysis, providing therefore a structural model for the assignment and analysis of ¹H NMR spectra of the complexes, which is strongly affected by the presence of paramagnetic lanthanide ions. Model validation was performed on complexes containing two different paramagnetic ions[Dy*,Gd] and [Gd*,Dy] as well as [Tb*,Tm] and [Tm*,Tb]synthesized by the above-mentioned method

A Molecular Chameleon: Reversible pH- and Cation-Induced Control of the Optical Properties of Phthalocyanine-Based Complexes in the Visible and Near-Infrared Spectral Ranges

A series of novel nonperipherally substituted tetra-15-crown-5-dibutoxyoxanthrenocyanines (H₂, Mg, Zn), acting as chameleons with the unique properties of switchable absorption and emission in the near-infrared (NIR) spectral range have been synthesized and characterized by X-ray diffraction. The attachment of 15-crown-5-α-dibutoxyoxanthreno moieties to phthalocyanine is responsible for the high solubility of the resulting molecules and the red shift of the Q band to the NIR region and offers a unique possibility for postsynthetic modification of the optical properties of the molecules. Both aggregation of phthalocyanine and its participation in an acid–base equilibrium strongly alter their optical properties. For example, the absorption of complexes can be reversibly tuned from 686 up to 1028 nm because of the cation-induced formation of supramolecular dimers or subsequent protonation of <i>meso</i>-N atoms orf macrocycle, in contrast to peripherally substituted tetra-15-crown-5-phthalocyanines without oxanthrene moieties. The reversibility of these processes can be controlled by the addition of [2.2.2]­cryptand or amines. All investigated compounds exhibit fluorescence with moderate quantum yield, which can also be switched between the ON and OFF states by the action of similar agents

Determination of the Structural Parameters of Heteronuclear (Phthalocyaninato)bis(crownphthalocyaninato)lanthanide(III) Triple-Deckers in Solution by Simultaneous Analysis of NMR and Single-Crystal X‑ray Data

Application of a general and convenient approach to the synthesis of heteronuclear crown-substituted triple-decker phthalocyaninates afforded two series of complexes containing one dia- and one paramagnetic Ln­(III) ion (for Y and almost the whole lanthanide family), [(15C5)₄Pc]­M*­[(15C5)₄Pc]­M­(Pc) (or [M*,M] for brevity sake), where (15C5) is 15-crown-5; (Pc^2–) is phthalocyaninato dianion; and M ≠ M* = Y, Nd, Eu, Tb, Dy, Ho, Er, Tm, Yb. This approach consists of using LaPc₂ as an efficient Pc^2– source. The solid-state structures of two complexes ([Tm*,Y] and [Yb*,Y]) were studied by single-crystal X-ray diffraction analysis, providing therefore a structural model for the assignment and analysis of ¹H NMR spectra of the complexes, which is strongly affected by the presence of paramagnetic lanthanide ions. Model validation was performed on complexes containing two different paramagnetic ions[Dy*,Gd] and [Gd*,Dy] as well as [Tb*,Tm] and [Tm*,Tb]synthesized by the above-mentioned method

Determination of the Structural Parameters of Heteronuclear (Phthalocyaninato)bis(crownphthalocyaninato)lanthanide(III) Triple-Deckers in Solution by Simultaneous Analysis of NMR and Single-Crystal X‑ray Data

Application of a general and convenient approach to the synthesis of heteronuclear crown-substituted triple-decker phthalocyaninates afforded two series of complexes containing one dia- and one paramagnetic Ln­(III) ion (for Y and almost the whole lanthanide family), [(15C5)₄Pc]­M*­[(15C5)₄Pc]­M­(Pc) (or [M*,M] for brevity sake), where (15C5) is 15-crown-5; (Pc^2–) is phthalocyaninato dianion; and M ≠ M* = Y, Nd, Eu, Tb, Dy, Ho, Er, Tm, Yb. This approach consists of using LaPc₂ as an efficient Pc^2– source. The solid-state structures of two complexes ([Tm*,Y] and [Yb*,Y]) were studied by single-crystal X-ray diffraction analysis, providing therefore a structural model for the assignment and analysis of ¹H NMR spectra of the complexes, which is strongly affected by the presence of paramagnetic lanthanide ions. Model validation was performed on complexes containing two different paramagnetic ions[Dy*,Gd] and [Gd*,Dy] as well as [Tb*,Tm] and [Tm*,Tb]synthesized by the above-mentioned method

A Molecular Chameleon: Reversible pH- and Cation-Induced Control of the Optical Properties of Phthalocyanine-Based Complexes in the Visible and Near-Infrared Spectral Ranges

A series of novel nonperipherally substituted tetra-15-crown-5-dibutoxyoxanthrenocyanines (H₂, Mg, Zn), acting as chameleons with the unique properties of switchable absorption and emission in the near-infrared (NIR) spectral range have been synthesized and characterized by X-ray diffraction. The attachment of 15-crown-5-α-dibutoxyoxanthreno moieties to phthalocyanine is responsible for the high solubility of the resulting molecules and the red shift of the Q band to the NIR region and offers a unique possibility for postsynthetic modification of the optical properties of the molecules. Both aggregation of phthalocyanine and its participation in an acid–base equilibrium strongly alter their optical properties. For example, the absorption of complexes can be reversibly tuned from 686 up to 1028 nm because of the cation-induced formation of supramolecular dimers or subsequent protonation of <i>meso</i>-N atoms orf macrocycle, in contrast to peripherally substituted tetra-15-crown-5-phthalocyanines without oxanthrene moieties. The reversibility of these processes can be controlled by the addition of [2.2.2]­cryptand or amines. All investigated compounds exhibit fluorescence with moderate quantum yield, which can also be switched between the ON and OFF states by the action of similar agents

A Molecular Chameleon: Reversible pH- and Cation-Induced Control of the Optical Properties of Phthalocyanine-Based Complexes in the Visible and Near-Infrared Spectral Ranges

A series of novel nonperipherally substituted tetra-15-crown-5-dibutoxyoxanthrenocyanines (H₂, Mg, Zn), acting as chameleons with the unique properties of switchable absorption and emission in the near-infrared (NIR) spectral range have been synthesized and characterized by X-ray diffraction. The attachment of 15-crown-5-α-dibutoxyoxanthreno moieties to phthalocyanine is responsible for the high solubility of the resulting molecules and the red shift of the Q band to the NIR region and offers a unique possibility for postsynthetic modification of the optical properties of the molecules. Both aggregation of phthalocyanine and its participation in an acid–base equilibrium strongly alter their optical properties. For example, the absorption of complexes can be reversibly tuned from 686 up to 1028 nm because of the cation-induced formation of supramolecular dimers or subsequent protonation of <i>meso</i>-N atoms orf macrocycle, in contrast to peripherally substituted tetra-15-crown-5-phthalocyanines without oxanthrene moieties. The reversibility of these processes can be controlled by the addition of [2.2.2]­cryptand or amines. All investigated compounds exhibit fluorescence with moderate quantum yield, which can also be switched between the ON and OFF states by the action of similar agents

Cation-Induced Dimerization of Crown-Substituted Phthalocyanines by Complexation with Rubidium Nicotinate As Revealed by X‑ray Structural Data

The supramolecular dimeric complex [(μ-oxo)­bis­(tetra-15-crown-5-phthalocyaninato)­(nicotinato)­aluminum­(III)]­tetra­(rubidium) bis­(nicotinate) was prepared by addition of an excess of a methanol solution of rubidium nicotinate to a chloroform solution of the aluminum crown-phthalocyaninate, [(HO)­Al­(15C5)₄Pc]. A single-crystal X-ray diffraction study of {[Rb₄(NicAl­(15C5)₄Pc)₂(μ-O)]²⁺(Nic^–)₂}·2.36HNic·11H₂O demonstrated that two molecules of the aluminum crown-phthalocyaninate nicotinate are connected through an Al–O–Al bridge supported by sandwiching of crown ether moieties by Rb⁺ cations

Phosphorus(V) Porphyrin-Based Molecular Turnstiles

A new cationic molecular turnstile based on a P­(V) porphyrin backbone bearing two pyridyl interaction sites, one at the meso position of the porphyrin and the other on the handle connected to the porphyrin through P–O bonds, was designed and synthesized. The dynamic behavior of the turnstile <b>2</b>, investigated by 1D and 2D ¹H NMR techniques, showed that in the absence of an effector, the turnstile is in its open state and undergoes a free rotation of the rotor (the handle) around the stator (the porphyrin backbone). In the presence of an external effector such as Ag⁺ cation or H⁺, the turnstile is switched to its closed states <b>2</b>-Ag⁺ and <b>2</b>-H⁺, respectively. The locking/unlocking process is reversible and may be achieved by precipitation of AgBr upon addition of Et₄NBr in the case of the silver-locked turnstile or by addition of Et₃N in the case of the proton-locked turnstile

Phosphorus(V) Porphyrin-Based Molecular Turnstiles

A new cationic molecular turnstile based on a P­(V) porphyrin backbone bearing two pyridyl interaction sites, one at the meso position of the porphyrin and the other on the handle connected to the porphyrin through P–O bonds, was designed and synthesized. The dynamic behavior of the turnstile <b>2</b>, investigated by 1D and 2D ¹H NMR techniques, showed that in the absence of an effector, the turnstile is in its open state and undergoes a free rotation of the rotor (the handle) around the stator (the porphyrin backbone). In the presence of an external effector such as Ag⁺ cation or H⁺, the turnstile is switched to its closed states <b>2</b>-Ag⁺ and <b>2</b>-H⁺, respectively. The locking/unlocking process is reversible and may be achieved by precipitation of AgBr upon addition of Et₄NBr in the case of the silver-locked turnstile or by addition of Et₃N in the case of the proton-locked turnstile

Phosphorus(V) Porphyrin-Based Molecular Turnstiles

A new cationic molecular turnstile based on a P­(V) porphyrin backbone bearing two pyridyl interaction sites, one at the meso position of the porphyrin and the other on the handle connected to the porphyrin through P–O bonds, was designed and synthesized. The dynamic behavior of the turnstile <b>2</b>, investigated by 1D and 2D ¹H NMR techniques, showed that in the absence of an effector, the turnstile is in its open state and undergoes a free rotation of the rotor (the handle) around the stator (the porphyrin backbone). In the presence of an external effector such as Ag⁺ cation or H⁺, the turnstile is switched to its closed states <b>2</b>-Ag⁺ and <b>2</b>-H⁺, respectively. The locking/unlocking process is reversible and may be achieved by precipitation of AgBr upon addition of Et₄NBr in the case of the silver-locked turnstile or by addition of Et₃N in the case of the proton-locked turnstile