Strongly blue fluorescent 1-phenyl-2-(pyridin-2-yl)-1H-phenanthro[9,10-d]imidazole(L1)is a facile block for the construction of multichromophore organic molecules,and simultaneously serves as a chelating diimine ligan...Strongly blue fluorescent 1-phenyl-2-(pyridin-2-yl)-1H-phenanthro[9,10-d]imidazole(L1)is a facile block for the construction of multichromophore organic molecules,and simultaneously serves as a chelating diimine ligand.The coordination of L1 to zinc halides enhances the intraligand charge transfer and decreases the emission energy.For the iodide derivative,intra-and intermolecular heavy atom effects lead to a dual singlet–triplet emission with a temperature-dependent ratio of fluorescence and phosphorescence bands in the crystalline state.Decoration of the anthracene core with pyridyl-phenanthroimidazole units(L2 and L3)changes the localization of the lowest energy electronic transitions to the former polyaromatic motif.The solid-state photophysical characteristics of L2 and L3-based compounds strongly depend on the intermolecular interactions between the constituting π-systems(phenanthrene and anthracene),which are perturbed by the ZnX2 coordinated fragments.Modulation of π-stacking contacts in these molecular materials containing L2 and L3 chromophores forms a basis for dynamic optical properties,responsive to mechanical,thermal,or chemical stimuli.展开更多
Coulomb’s law predicts that like-charge ions repel and avoid dimerization.However,a class of dimers between like-charge ions is characterized.The[3,3’-Fe(1,2-C_(2)B_(9)H_(11))_(2)]−(abbreviated as[o-FESAN]−)represen...Coulomb’s law predicts that like-charge ions repel and avoid dimerization.However,a class of dimers between like-charge ions is characterized.The[3,3’-Fe(1,2-C_(2)B_(9)H_(11))_(2)]−(abbreviated as[o-FESAN]−)represents an innovative non-classical inorganic anion apart from hydroxyanions that exhibits anion-anion stabilization via dihydrogen bonding.Experimental methods(nuclear magnetic resonance[NMR],dynamic light scattering[DLS],and X-ray diffraction)and theoretical approaches(density functional theory)reveal that[o-FESAN]−clusters aggregate by overcoming long-range electrostatic repulsion.The synthesis of[H_(3)O][o-FESAN]∙3H_(2)O and its crystal structure confirm the formation of stabilized anion-anion aggregates,with[H_(3)O]^(+) counterions residing freely in the channels rather than between the anionic clusters.The structure exhibits the cisoid rotamer,which facilitates the ability of the anionic[o-FESAN]−cluster to form interactions stabilized by dihydrogen bonds(head-to-middle cluster)shorter than the sum of the Van der Waals radii.These shorter bonds are crucial for the formation of anion-anion interactions mediated by dihydrogen bonds.X-ray structures show that anions aggregate in the solid state,overcoming longrange electrostatic repulsion through dihydrogen bonds,which are distinct from the hydrogen bonds commonly observed in anion systems involving highly electronegative elements.Consistent with crystal structure evidence,1H NMR,transmission electron microscopy,and DLS confirm[o-FESAN]−anion-anion aggregates in solution.Theoretical calculations support the formation of these anion-anion aggregates,primarily via C_(cluster)-H⋅⋅⋅H-B bonds.While individual B-H⋅⋅⋅H-B interactions are weakly attractive,their cumulative effect significantly enhances aggregate stability.Additionally,the crystal structure of Na(H_(2)O)_(3)[o-FESAN]is reported and analyzed,providing further evidence of unconventional interactions stabilized by dihydrogen bonds.展开更多
基金the Academy of Finland(decision 317903,I.O.K.,Flagship Programme,Photonics Research and Innovation PREIN,decision 320166)the Russian Science Foundation(grant 19-73-20055,J.R.S.,photophysical studies)is gratefully acknowledged.
文摘Strongly blue fluorescent 1-phenyl-2-(pyridin-2-yl)-1H-phenanthro[9,10-d]imidazole(L1)is a facile block for the construction of multichromophore organic molecules,and simultaneously serves as a chelating diimine ligand.The coordination of L1 to zinc halides enhances the intraligand charge transfer and decreases the emission energy.For the iodide derivative,intra-and intermolecular heavy atom effects lead to a dual singlet–triplet emission with a temperature-dependent ratio of fluorescence and phosphorescence bands in the crystalline state.Decoration of the anthracene core with pyridyl-phenanthroimidazole units(L2 and L3)changes the localization of the lowest energy electronic transitions to the former polyaromatic motif.The solid-state photophysical characteristics of L2 and L3-based compounds strongly depend on the intermolecular interactions between the constituting π-systems(phenanthrene and anthracene),which are perturbed by the ZnX2 coordinated fragments.Modulation of π-stacking contacts in these molecular materials containing L2 and L3 chromophores forms a basis for dynamic optical properties,responsive to mechanical,thermal,or chemical stimuli.
基金the Xray acquisition data of the[H3O][o-FESAN]∙3H2O(H[o-FESAN])F.Teixidor and C.Vinas gratefully acknowledge the support of the Generalitat de Catalunya(Departament d’Agricultura,Ramaderia,Pesca i Alimentacio)through project ACC_2023_EXP_SIA002_40_0002222+1 种基金The Severo Ochoa Program for Centers of Excellence in R&D(CEX2023-001263-S)is acknowledgeWe acknowledge grants of computer capacity from the Finnish Grid and Cloud Infrastructure(persistent identifier urn:nbn:fi:research-infras-2016072533).
文摘Coulomb’s law predicts that like-charge ions repel and avoid dimerization.However,a class of dimers between like-charge ions is characterized.The[3,3’-Fe(1,2-C_(2)B_(9)H_(11))_(2)]−(abbreviated as[o-FESAN]−)represents an innovative non-classical inorganic anion apart from hydroxyanions that exhibits anion-anion stabilization via dihydrogen bonding.Experimental methods(nuclear magnetic resonance[NMR],dynamic light scattering[DLS],and X-ray diffraction)and theoretical approaches(density functional theory)reveal that[o-FESAN]−clusters aggregate by overcoming long-range electrostatic repulsion.The synthesis of[H_(3)O][o-FESAN]∙3H_(2)O and its crystal structure confirm the formation of stabilized anion-anion aggregates,with[H_(3)O]^(+) counterions residing freely in the channels rather than between the anionic clusters.The structure exhibits the cisoid rotamer,which facilitates the ability of the anionic[o-FESAN]−cluster to form interactions stabilized by dihydrogen bonds(head-to-middle cluster)shorter than the sum of the Van der Waals radii.These shorter bonds are crucial for the formation of anion-anion interactions mediated by dihydrogen bonds.X-ray structures show that anions aggregate in the solid state,overcoming longrange electrostatic repulsion through dihydrogen bonds,which are distinct from the hydrogen bonds commonly observed in anion systems involving highly electronegative elements.Consistent with crystal structure evidence,1H NMR,transmission electron microscopy,and DLS confirm[o-FESAN]−anion-anion aggregates in solution.Theoretical calculations support the formation of these anion-anion aggregates,primarily via C_(cluster)-H⋅⋅⋅H-B bonds.While individual B-H⋅⋅⋅H-B interactions are weakly attractive,their cumulative effect significantly enhances aggregate stability.Additionally,the crystal structure of Na(H_(2)O)_(3)[o-FESAN]is reported and analyzed,providing further evidence of unconventional interactions stabilized by dihydrogen bonds.
