Synthesis of tetraarylborates via tetralithio intermediates and the effect of polar functional groups and cations on their crystal structures.

A novel general protocol for the preparation of functionalized (COOH, CHO, C(O)NHtBu, B(OH)2) tetraphenyl- and tetrakis(4'-biphenylyl)borates is reported. It involves four-fold halogen-lithium exchange in potassium tetrakis(iodophenyl)borates and tetrakis(4'-bromobiphenylyl)borate) using t-BuLi in THF at -78 °C followed by treatment of the resulting tetralithio intermediates with electrophiles (CO2, DMF, t-BuNCO, B(OMe)3). X-ray crystal structures of ammonium tetrakis[4-(dihydroxyboryl)phenyl]borate, lithium tetrakis(3-carboxyphenyl)borate, and lithium tetrakis[4-(tert-butylcarbamoyl)phenyl]borate were determined showing a strong effect of the cation and polar functional group on supramolecular architecture.

Hybrid Triazine-Boron Two-Dimensional Covalent Organic Frameworks: Synthesis, Characterization, and DFT Approach to Layer Interaction Energies.

The conversion of 2,4,6-tris(4'-bromophenyl)-1,3,5-triazine to the respective triboronic acid was successfully accomplished by a simple triple Br/Li exchange followed by boronation. Further dehydrative condensation reactions with 2,3,6,7,10,11-hexahydroxytriphenylene or 2,3,6,7-tetrahydroxy-9,10-dilalkylanthracenes (R = Me, Et) resulted in materials featuring good porosity and sorption properties with the nitrogen uptake exceeding 500 cm/g (STP) and S up to 1267 m/g (T = 77.2 K).

Highly Fluorescent Red-Light Emitting Bis(boranils) Based on Naphthalene Backbone.

Ten bis(boranils) differently substituted at the boron atom and iminophenyl groups were synthesized from 1,5-dihydroxynaphthalene-2,6-dicarboxaldehyde using a simple one-pot protocol. Their photophysical properties can be easily tuned in a wide range by the variation of substituents. Their absorption and emission spectral bands are significantly red-shifted (λ = 495-590 nm, λ = 533-683 nm) when compared with simple boranils, whereas fluorescence quantum yields are strongly improved to reach 83%.

Crystal structure of (2',3,6'-tri-chloro-biphenyl-2-yl)boronic acid tetra-hydro-furan monosolvate.

The title compound, C12H8BCl3O2·C4H8O, crystallizes as a tetra-hydro-furan monosolvate. The boronic acid group adopts a syn-anti conformation and is significantly twisted along the carbon-boron bond by 69.2 (1)°, due to considerable steric hindrance from the 2',6'-di-chloro-phenyl group that is located ortho to the boronic acid substituent.

Tuning of the colour and chemical stability of model boranils: a strong effect of structural modifications.

A series of diarylborinic complexes with salicydeneaniline ligands bearing various functional groups at the 6-position have been synthesized in high yields by applying a straightforward one-pot multicomponent protocol. UV-Vis measurements revealed the influence of electronic character of substituents on the observed maximum of emission (λem). This has been confirmed by a relatively strong linear correlation (R(2) = 0.

Crystal structure of (2-benzyl-oxy-pyrimidin-5-yl)boronic acid.

The boronic acid group in the title compound, C11H11BN2O3, adopts a syn-anti conformation and is almost coplanar with the aromatic rings , making a dihedralangle of 3.8 (2)°. In the crystal, adjacent mol-ecules are linked via pairs of O-H⋯O inter-actions, forming centrosymmetric dimers with an R 2 (2)(8) motif, which have recently been shown to be energetically very favorable (Durka et al.

Charge transfer properties of two polymorphs of luminescent (2-fluoro-3-pyridyl)(2,2'-biphenyl)borinic 8-oxyquinolinate.

Single crystal X-ray structures of two polymorphs of (2-fluoro-3-pyridyl)(2,2'-biphenyl)borinic 8-oxyquinolinate: orthorhombic (space group Pca21), and triclinic (space group P1̄) have been established and analysed. A fast rate of crystallization results in the orthorhombic polymorph, whereas slow crystallization gives the triclinic polymorph. Physicochemical and theoretical results prove that both polymorphs form similar crystals with very similar geometry of molecules.

2-Meth-oxy-3-(tri-methyl-sil-yl)phenyl-boronic acid.

The mol-ecular structure of the title compound, C10H17BO3Si, features an intra-molecular O-H⋯O hydrogen bond; the boronic group group has an exo-endo conformation. In the crystal, the mol-ecules inter-act with each other by O-H⋯O hydrogen bonds, producing centrosymmetric dimers that are linked by weak π-π stacking inter-actions featuring specific short B⋯C contacts [e.g.

Competition between hydrogen and halogen bonding in the structures of 5,10-dihydroxy-5,10-dihydroboranthrenes.

X-ray crystallographic and computational studies are reported for a series of boranthrenes, substituted with halogen atoms. The role of competitive hydrogen (O-H..

Heteroleptic (2-fluoro-3-pyridyl)arylborinic 8-oxyquinolinates for the potential application in organic light-emitting devices.

A one-pot protocol has been developed to obtain a series of luminescent heteroleptic diarylborinic complexes bearing the 2-fluoro-3-pyridyl and another aryl group attached to the boron atom chelated with a simple or functionalized 8-oxyquinolinato ligand. The tetrahedral geometry around the boron atom in all compounds has been established by the (11)B NMR spectroscopy and/or X-ray diffraction technique. In the solution, the obtained complexes have emission maxima ranging from 502 to 525 nm at room temperature.

(N→B)-4-Methyl-3-pyrid-yl[N-methyl-imino-diacetate-O,O',N]borane.

The title compound, C(11)H(13)BN(2)O(4), has a rigid bicyclic structure due to an intra-molecular nitro-gen-boron dative bond. The B atom is in a distorted tetra-hedron environment with a B-N bond length of 1.640 (2) Å, which is in good comparison with the values in analogues compounds.

Ammonia-triphenyl-borane.

The asymmetric unit of the title compound, C(18)H(18)BN or (C(6)H(5))(3)B·NH(3), comprises two crystallographically independent but virtually identical mol-ecules. Mol-ecules of one type are linked with each other by N-H⋯π inter-actions, generating an infinite column aligned along the b-axis direction. The columns of different types of mol-ecules are inter-connected by C-H⋯π inter-actions, producing a three-dimensional array.

(2,4-Dipropoxyphen-yl)boronic acid.

In the crystal, the title compound, C(12)H(19)BO(4), exists as a centrosymmetric O-H⋯O hydrogen-bonded dimer. Dimers are linked via C-H⋯O hydrogen bonds, generating an infinite zigzag chain oriented parallel to [1[Formula: see text]1]. The chains are assembled, giving sheets aligned parallel to (21[Formula: see text]) and inter-connected by weak C-H⋯π inter-actions, producing a three-dimensional network.

On the nature of the B...N interaction and the conformational flexibility of arylboronic azaesters.

It is shown that the structural and physicochemical properties of arylboronic azaesters result from the properties of the key B-N bond. This bond is different in arylboronic azaesters from typical single/double/triple B-N bonds present in other boron-nitrogen compounds. By studying a model example, 6-tert-butyl-2-(3',5'-difluorophenyl)-(N-B)-1,3,6,2-dioxazaborocane, it is proved that the molecule adopts the closed form in the solid state with the BN bond length equal to 1.

1,2:3,5-Bis[(4-tert-butyl-phen-yl)boranedi-yl]-α-d-glucofuran-ose.

The crystal structure of the title compound, C(26)H(34)B(2)O(6), comprises two crystallographically independent mol-ecules. In the crystal, the mol-ecules are linked by multiple inter-molecular O-H⋯O and C-H⋯O hydrogen bonds into a two-dimensional array.

Mesit-yl(2,4,6-trimeth-oxy-phen-yl)borinic acid.

In the title mol-ecule, C(18)H(23)BO(4), the dihedral angle between the least-squares planes of the aromatic rings is 84.88 (3)°. The B atom deviates by 0.

2,4-Dibutoxy-phenyl-boronic acid.

In the crystal of the title compound, C(14)H(23)BO(4), centrosymmetric dimers linked by pairs of O-H⋯O hydrogen bonds occur. The dimers are linked via C-H⋯O contacts, generating a two-dimensional array parallel to (12). These are inter-connected by weak O-H⋯O hydrogen bonds, as well as C-H⋯π inter-actions.

{2-[(2,6-Difluoro-phen-oxy)meth-yl]phen-yl}boronic acid.

The planes of the two benzene rings in the mol-ecule of the title compound, C(13)H(11)BF(2)O(3), form a dihedral angle of 76.06 (3)°; the C-O-C-C torsion angle characterizing the conformation of the central link of the mol-ecule is -79.20 (1)°.

[3-Bromo-2-(3-fluoro-benz-yloxy)phen-yl]boronic acid.

In the title compound, C(13)H(11)BBrFO(3), the dioxy-boron fragment is close to co-planar with the benzene ring to which the B atom is connected [dihedral angle = 8.96 (4)°]. The dihedral angle between the two benzene rings is 14.

tert-Butyl 2-(dihydroxyboryl)pyrrole-1-carboxylate.

In the title compound, C(9)H(14)BNO(4), the carbonyl and boronic acid groups are essentially coplanar with the pyrrole ring and the boronic acid group has an exo-endo conformation. The exo-oriented OH is engaged in an intra-molecular O-H⋯O inter-action, while the endo-oriented one is involved in inter-molecular hydrogen bonding to form centrosymmetric dimers. A supra-molecular assembly is achieved through inter-actions involving the tert-butyl groups, forming infinite chains along the crystallographic b axis.

(2-Butoxy-phen-yl)boronic acid.

The title compound, 2-(CH(3)CH(2)CH(2)CH(2)O)C(6)H(4)B(OH)(2), exists as a centrosymmetric hydrogen-bonded dimer. Dimers are linked via C-H⋯π and π-π [with closest C⋯C contact of 3.540 (3) Å] inter-actions to produce a two-dimensional array.

(2-Meth-oxy-1,3-phenyl-ene)diboronic acid.

The mol-ecular structure of the title compound, 2-CH(3)O-C(6)H(3)-1,3-[B(OH)(2)](2) or C(7)H(10)B(2)O(5), features two intra-molecular O-H⋯O hydrogen bonds of different strengths. One of the boronic acid groups is almost coplanar with the aromatic ring, whereas the second is significantly twisted. Mol-ecules are linked by inter-molecular O-H⋯O hydrogen bonds, generating infinite chains cross-linked to form a two-dimensional sheet structure aligned parallel to the (01) plane.

2,3-Difluoro-4-formylphenylboronic acid.

The molecule of the title compound, 2,3-F(2)-4-(CHO)C(6)H(2)B(OH)(2) or C(7)H(5)BF(2)O(3), contains a formyl group coplanar with the benzene ring. The boronic acid group is twisted with respect to the benzene ring plane. The molecules are organized into infinite chains via intermolecular O-H.

(2-Methoxy-3-pyridyl)boronic acid.

The structure of the title compound, 2-CH3O-C5H3N-3-B(OH)2 or C6H8BNO3, comprises two crystallographically independent molecules. The molecules are linked to each other by intermolecular O-H..

2-(Methoxycarbonyl)phenylboronic acid.

The structure of the title compound, 2(CH3OCO)C6H4B(OH)2 or C8H9BO4, involves two crystallographically independent conformers, A and B, in a 1:2 ratio; molecules of conformer A are located on a crystallographic mirror plane. The most striking difference between the two independent molecules is the opposite orientation of the methoxycarbonyl groups, while the conformations of the boronic acid groups vary more subtly. Molecules of both types are ordered to produce a specific hydrogen-bonding network that can be interpreted in terms of a layer lying parallel to (100).