Synthesis of Meso-Substituted Subphthalocyanine–Subporphyrin Hybrids: Boron Subtribenzodiazaporphyrins**

The first syntheses of hybrid structures that lie between subphthalocyanines and subporphyrins are reported. The versatile single-step synthetic method uses a preformed aminoisoindolene to provide the bridging methine unit and its substituent while trialkoxyborates simultaneously act as Lewis acid, template, and provider of the apical substituent. The selection of each component therefore allows for the controlled formation of diverse, differentially functionalized systems. The new hybrids are isolated as robust, pure materials that display intense absorption and emission in the mid-visible region. The new compounds are further characterized in solution and solid state by variable-temperature NMR spectroscopy and X-ray crystallography, respectively.


General methods:
Reagents and solvents were purchased from commercial sources and used without further purification, with the following exceptions: phthalonitrile was recrystallized from hot xylene; recrystallizations were performed using distilled solvents. 1 H, 13 C, 11 B, 19 F-NMR spectra were recorded at 500.1, 125.7, 160.5 and 470.4 MHz, respectively, using a Bruker AscendTM 500. The residual solvent peaks were used as references in the case of 1 H and 13 C, and the instrument calibrated with external references such as BF3⋅OEt2 for 11 B-NMR and CFCl3 for 19 F-NMR.
Spectra of SubTBDAPs are of recrystallized samples (distilled dichloromethane/distilled petroleum ether). 2D COSY, NOESY and ROESY experiments were used to assist with the NMR spectroscopy assignments. Microwave reactions used a Biotage Initiator 2.5 reactor (400W) equipped with an external temperature sensor. Thin layer chromatography (TLC) was carried out on aluminium sheets coated with silica gel 60 F252 (Merck), with visualization by UV light and by charring with 0.1% ninhydrin in EtOH when necessary. Column chromatography was carried out on silica gel Davisil® LC60A 40-63 micron (Grace GmbH & Co). MALDI-TOF mass spectra were obtained using a Shimadzu Biotech Axima instrument. High resolution mass spectrometry was performed by the ESPRC UK National Mass Spectrometry Service Centre at Swansea. UV-Vis and emission spectra were recorded at room temperature on a Hitachi U-3000 spectrophotometer and on a Hitachi F-4500 fluorescence spectrophotometer, respectively. Melting points were measured using a Reichert Thermovar microscope with a thermopar based temperature control. X-Ray crystallography data was collected and analysed by Dr Simon J. Coles and Dr Graham J. Tizzard at the UK National Crystallography Service at Southampton and by Dr David Hughes at UEA. NMR calculations (supporting assignment of Ho and Ho') were computed at the BP86-D3/def2-SVP level of theory. The calculations have been performed using the program TURBOMOLE version 6.4. 1 For the calculations we have used the BP86 2 functional.

Fluorescence quantum yield:
The fluorescence quantum yield (Φ ) values of SubTBDAPs were measured in DCM, due to good solubility of the compounds in this solvent. The measurements were performed under aerobic conditions. The quantum yields were determined using Rhodamine B in MeOH as fluorescence standard; 3 it presents similar UV-Vis absorption and fluorescence maxima to the new compounds. λexc = 500 nm was chosen to obtain the emission spectra of each compound, since both standard and unknown compounds show similar absorbance at this wavelength. The Φ values were calculated using equation 1: Where Φ is the quantum yield, IA the integrated area under the emission curve, η the refractive index of the solvents, and u and s are the subscripts used to refer to the unknown and the standard, respectively. Aminoisoindolenes 12, [4] 18 [5] and 19 [6] were prepared as previously described in literature.

meso-PhenylSubTBDAP-OPh (13)
A single crystal suitable for X-ray analysis was prepared by recrystallization from a mixture of acetone/hexane. Crystals are red prisms. From a sample under oil, one, ca 0.05 x 0.10 x 0.41 mm, was mounted on a glass fibre and fixed in the cold nitrogen stream on an Oxford Diffraction Xcalibur-3/Sapphire3-CCD diffractometer, equipped with Mo-Kα radiation and graphite monochromator. Intensity data were measured by thin-slice ω-and φ-scans. Total no. of reflections recorded, to θmax = 21.5°, was 24461 of which 3107 were unique (Rint = 0.111); 2074 were 'observed' with I > 2σI. Data were processed using the CrysAlisPro-CCD and -RED (1) programs. The structure was determined by the direct methods routines in the SHELXS program (2A) and refined by full-matrix least-squares methods, on F 2 's, in SHELXL (2B). The non-hydrogen atoms were refined with anisotropic thermal parameters. Hydrogen atoms in the main molecule were included in idealised positions and their Uiso values were set to ride on the Ueq values of the parent carbon atoms. There were a number of persistent difference peaks in the neighbourhood of the solvent water oxygen atom, O(6), and four of these were included as hydrogen atoms which were refined freely; two appear close to likely sites as part of the water molecule, whilst two were further from the oxygen atom and might be indications of site disorder of the solvent molecule. At the conclusion of the refinement, wR2 = 0.140 and R1 = 0.098 (2B) for all 3107 reflections weighted w = [σ 2 (Fo 2 ) + (0.0631P) 2 ] -1 with P = (Fo 2 + 2Fc 2 )/3; for the 'observed' data only, R1 = 0.057. In the final difference map, the highest peak (ca 0.23 eÅ -3 ) was near H(37) . Scattering factors for neutral atoms were taken from reference (3). Computer programs used in this analysis have been noted above, and were run through WinGX (4) on a Dell Optiplex GX620 PC at the University of East Anglia. References

meso-PhenylSubTBDAP-O i Pr (15)
A single crystal suitable for X-Ray analysis was grown from a mixture of cyclohexane/acetone. Red block crystals were poorly diffracting with no significant data beyond 0.84Å. The data were collected on a Rigaku Saturn 724+ area detector mounted at the window of an FR-E+ rotating anode generator with a Mo anode and equipped with an Oxford Cryosystems cryostream device. Rigaku CrystalClear [1] was used to record images and for data integration. The structure was solved by charge-flipping methods using SUPERFLIP [2] and refined on Fo 2 by full-matrix least squares refinement using SHELXL-2014. [3] All non-hydrogen atoms were refined with anisotropic displacement parameters. Hydrogen atoms were added at calculated positions and refined using a riding model with isotropic displacement parameters based on the equivalent isotropic displacement parameter (Ueq) of the parent atom. The isopropoxide substituent is disordered over two positions (60:40). The structure was deposited on the Cambridge Structural Database with the deposition number CCDC

meso-PhenylSubTBDAP-OMe (16)
Crystals suitable for X-Ray analysis were grown dissolving SubTBDAP 16 in a mixture of dichloromethane/hexane and allowing slow diffusion with acetone. Red plate crystals gave good diffraction. The data were collected on a Rigaku Saturn 724+ area detector mounted at the window of an FR-E+ rotating anode generator with a Mo anode and equipped with an Oxford Cryosystems cryostream device. Rigaku CrystalClear [1] was used to record images and for data integration. The structure was solved by chargeflipping methods using SUPERFLIP [2] and refined on Fo 2 by full-matrix least squares refinement using SHELXL-2013. [3] All non-hydrogen atoms were refined with anisotropic displacement parameters. Hydrogen atoms were added at calculated positions and refined using a riding model with isotropic displacement parameters based on the equivalent isotropic displacement parameter (Ueq) of the parent atom. The structure was deposited on the Cambridge Structural Database with the deposition number CCDC 1044583.

meso-PhenylSubTBDAP-OBu (17)
Crystals suitable for X-Ray were grown dissolving SubTBDAP 17 in a mixture of dichloromethane/acetone allowing slow diffusion of cyclohexane. Red plate crystals were poorly diffracting with no significant data beyond 0.84Å. The data were collected on a Rigaku Saturn 724+ area detector mounted at the window of an FR-E+ rotating anode generator with a Mo anode and equipped with an Oxford Cryosystems cryostream device. Rigaku CrystalClear [1] was used to record images and Agilent CrysAlisPro [4] was used for data integration. The structure was solved by charge-flipping methods using SUPERFLIP [2] and refined on Fo 2 by full-matrix least squares refinement using SHELXL-2014. [3] All non-hydrogen atoms were refined with anisotropic displacement parameters. Hydrogen atoms were added at calculated positions and refined using a riding model with isotropic displacement parameters based on the equivalent isotropic displacement parameter (Ueq) of the parent atom. The structure was deposited on the Cambridge Structural Database with the deposition number CCDC 1044584.

meso-(4-Methoxyphenyl)SubTBDAP-OMe (24)
Crystals suitable for X-Ray analysis were grown by dissolving SubTBDAP 24 in a mixture of dichloromethane/acetone and allowing slow diffusion of methanol. The data were collected on a Rigaku Saturn 724+ area detector mounted at the window of an FR-E+ rotating anode generator with a Mo anode and equipped with an Oxford Cryosystems cryostream device. Rigaku CrystalClear [1] was used to record images and Agilent CrysAlisPro [4] was used for data integration. The structure was solved by charge-flipping methods using SUPERFLIP [2] and refined on Fo 2 by full-matrix least squares refinement using SHELXL-2014. [3] All non-hydrogen atoms were refined with anisotropic displacement parameters. Hydrogen atoms were added at calculated positions and refined using a riding model with isotropic displacement parameters based on the equivalent isotropic displacement parameter (Ueq) of the parent atom. The structure was deposited on the Cambridge Structural Database with the deposition number CCDC 1044585.