scholarly journals Manipulating the Conformation of 3,2′:6′,3″-Terpyridine in [Cu2(μ-OAc)4(3,2′:6′,3″-tpy)]n 1D-Polymers

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 182-198
Author(s):  
Dalila Rocco ◽  
Samantha Novak ◽  
Alessandro Prescimone ◽  
Edwin C. Constable ◽  
Catherine E. Housecroft

We report the preparation and characterization of 4′-([1,1′-biphenyl]-4-yl)-3,2′:6′,3″-terpyridine (1), 4′-(4′-fluoro-[1,1′-biphenyl]-4-yl)-3,2′:6′,3″-terpyridine (2), 4′-(4′-chloro-[1,1′-biphenyl]-4-yl)-3,2′:6′,3″-terpyridine (3), 4′-(4′-bromo-[1,1′-biphenyl]-4-yl)-3,2′:6′,3″-terpyridine (4), and 4′-(4′-methyl-[1,1′-biphenyl]-4-yl)-3,2′:6′,3″-terpyridine (5), and their reactions with copper(II) acetate. Single-crystal structures of the [Cu2(μ-OAc)4L]n 1D-coordination polymers with L = 1–5 have been determined, and powder X-ray diffraction confirms that the single crystal structures are representative of the bulk samples. [Cu2(μ-OAc)4(1)]n and [Cu2(μ-OAc)4(2)]n are isostructural, and zigzag polymer chains are present which engage in π-stacking interactions between [1,1′-biphenyl]pyridine units. 1D-chains nest into one another to give 2D-sheets; replacing the peripheral H in 1 by an F substituent in 2 has no effect on the solid-state structure, indicating that bifurcated contacts (H...H for 1 or H...F for 2) are only secondary packing interactions. Upon going from [Cu2(μ-OAc)4(1)]n and [Cu2(μ-OAc)4(2)]n to [Cu2(μ-OAc)4(3)]n, [Cu2(μ-OAc)4(4)]n, and [Cu2(μ-OAc)4(5)]n·nMeOH, the increased steric demands of the Cl, Br, or Me substituent induces a switch in the conformation of the 3,2′:6′,3″-tpy metal-binding domain, and a concomitant change in dominant packing interactions to py–py and py–biphenyl face-to-face π-stacking. The study underlines how the 3,2′:6′,3″-tpy domain can adapt to different steric demands of substituents through its conformational flexibility.

Inorganics ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 54
Author(s):  
Giacomo Manfroni ◽  
Simona S. Capomolla ◽  
Alessandro Prescimone ◽  
Edwin C. Constable ◽  
Catherine E. Housecroft

The isomers 4′-(4-(trifluoromethyl)phenyl)-4,2′:6′,4″-terpyridine (1), 4′-(3-(trifluoromethyl)phenyl)-4,2′:6′,4″-terpyridine (2), 4′-(4-(trifluoromethyl)phenyl)-3,2′:6′,3″-terpyridine (3), and 4′-(3-(trifluoromethyl)phenyl)-3,2′:6′,3″-terpyridine (4) have been prepared and characterized. The single crystal structures of 1 and 2 were determined. The 1D-polymers [Cu2(hfacac)4(1)2]n.2nC6H4Cl2 (Hhfacac = 1,1,1,5,5,5-hexafluoropentane-2,4-dione), [Cu(hfacac)2(2)]n.2nC6H5Me, [Cu2(hfacac)4(3)2]n.nC6H4Cl2, [Cu2(hfacac)4(3)2]n.nC6H5Cl, and [Cu(hfacac)2(4)]n.nC6H5Cl have been formed by reactions of 1, 2, 3 and 4 with [Cu(hfacac)2].H2O under conditions of crystal growth by layering and four of these coordination polymers have been formed on a preparative scale. [Cu2(hfacac)4(1)2]n.2nC6H4Cl2 and [Cu(hfacac)2(2)]n.2nC6H5Me are zig-zag chains and the different substitution position of the CF3 group in 1 and 2 does not affect this motif. Packing of the polymer chains is governed mainly by C–F...F–C contacts, and there are no inter-polymer π-stacking interactions. The conformation of the 3,2′:6′,3″-tpy unit in [Cu2(hfacac)4(3)2]n.nC6H4Cl2 and [Cu(hfacac)2(4)]n.nC6H5Cl differs, leading to different structural motifs in the 1D-polymer backbones. In [Cu(hfacac)2(4)]n.nC6H5Cl, the peripheral 3-CF3C6H4 unit is accommodated in a pocket between two {Cu(hfacac)2} units and engages in four C–Hphenyl...F–Chfacac contacts which lock the phenylpyridine unit in a near planar conformation. In [Cu2(hfacac)4(3)2]n.nC6H4Cl2 and [Cu(hfacac)2(4)]n.nC6H5Cl, π-stacking interactions between 4′-trifluoromethylphenyl-3,2′:6′,3″-tpy domains are key packing interactions, and this contrasts with the packing of polymers incorporating 1 and 2. We use powder X-ray diffraction to demonstrate that the assemblies of the coordination polymers are reproducible, and that a switch from a 4,2′:6′,4″- to 3,2′:6′,3″-tpy metal-binding unit is accompanied by a change from dominant C–F...F–C and C–F...H–C contacts to π-stacking of arene domains between ligands 3 or 4.


Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1663 ◽  
Author(s):  
Dalila Rocco ◽  
Alessandro Prescimone ◽  
Edwin C. Constable ◽  
Catherine E. Housecroft

The synthesis and characterization of 4′-(4-n-propoxyphenyl)-3,2′:6′,3″-terpyridine is described. Five 2D-coordination networks have been isolated by crystal growth at room temperature from reactions of Co(NCS)2 with 4′-(4-n-alkyloxyphenyl)-3,2′:6′,3″-terpyridines in which the n-alkyl group is ethyl, n-propyl, n-butyl, n-pentyl and n-hexyl in ligands 2–6, respectively. The single-crystal structures of [{Co(2)2(NCS)2}.0.6CHCl3]n, [{Co(3)2(NCS)2}.4CHCl3.0.25H2O]n, [{Co(4)2(NCS)2}.4CHCl3]n, [Co2(5)4(NCS)4]n and [Co(6)2(NCS)2]n have been determined, and powder X-ray diffraction has demonstrated that the single-crystal structures are representative of the bulk materials. Each compound possesses a (4,4) net with Co centres as 4-connecting nodes. For the assemblies containing 2, 3 and 4, the (4,4) net comprises two geometrically different rhombuses, and the nets pack in an ABAB... arrangement with cone-like arrangements of n-alkyloxyphenyl groups being accommodated in a similar unit in an adjacent net. An increase in the n-alkyloxy chain length has two consequences: there is a change in the conformation of the 3,2′:6′,3″-tpy metal-binding domain, and the (4,4) net comprises identical rhombuses. Similarities and differences between the assemblies with ligands 2–6 and the previously reported [{Co(1)2(NCS)2}.3MeOH]n and [{Co(1)2(NCS)2}.2.2CHCl3]n in which 1 is 4′-(4-methoxyphenyl)-3,2′:6′,3″-terpyridine are discussed. The results demonstrate the effects of combining a variable chain length in the 4′-(4-n-alkyloxyphenyl) substituents of 3,2′:6′,3″-tpy and a conformationally flexible 3,2′:6′,3″-tpy metal-binding domain.


Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 325
Author(s):  
Giacomo Manfroni ◽  
Alessandro Prescimone ◽  
Edwin Constable ◽  
Catherine Housecroft

We have prepared and characterized 1,4-dibromo-2,5-bis(2-phenylethoxy)benzene (1) and 1,4-dibromo-2,5-bis(3-phenylpropoxy)benzene (2). Their single-crystal structures confirm that, at the molecular level, they are similar with the phenylalkoxy chains in extended conformations. However, there are significant differences in packing interactions. The packing in 1 is dominated by C–Br...π(arene) interactions, with each Br located over one C–C bond of the central arene ring of an adjacent molecule. In contrast, the packing of molecules of 2 involves a combination of C–H...Br hydrogen bonds, Br...Br interactions, and arene–arene π-stacking. The single-crystal structures of both orthorhombic and triclinic polymorphs of 1 have been determined and the packing interactions are shown to be essentially identical.


Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3162 ◽  
Author(s):  
Dalila Rocco ◽  
Alessandro Prescimone ◽  
Edwin C. Constable ◽  
Catherine E. Housecroft

The preparation and characterization of 4′-(4-n-octyloxyphenyl)-3,2′:6′,3″-terpyridine (8) and 4′-(4-n-nonyloxyphenyl)-3,2′:6′,3″-terpyridine (9) are reported. The single crystal structures of 4′-(4-n-hexyloxyphenyl)-3,2′:6′,3″-terpyridine (6), 4′-(4-n-heptyloxyphenyl)-3,2′:6′,3″-terpyridine (7), and compounds 8 and 9 have been determined. The conformation of the 3,2′:6′,3″-tpy unit is trans,trans in 6 and 7, but switches to cis,trans in 8 and 9. This is associated with significant changes in the packing interactions with a more dominant role for van der Waals interactions between adjacent n-alkyloxy chains and C–Hmethylene... π interactions in 8 and 9. The solid-state structures of 6 and 7 with the n-hexyloxy and n-heptyloxy chains feature interwoven sheets of supramolecular assemblies of molecules, with pairs of n-alkyloxy chains threaded through cavities in an adjacent sheet.


CrystEngComm ◽  
2015 ◽  
Vol 17 (42) ◽  
pp. 8047-8057 ◽  
Author(s):  
Emily R. Draper ◽  
Kyle L. Morris ◽  
Marc A. Little ◽  
Jaclyn Raeburn ◽  
Catherine Colquhoun ◽  
...  

A number of Fmoc amino acids can be effective low molecular weight hydrogelators; we compare single crystal structures to fibre X-ray diffraction data.


2006 ◽  
Vol 84 (2) ◽  
pp. 238-242 ◽  
Author(s):  
Jonathan C Collings ◽  
Andrei S Batsanov ◽  
Judith AK Howard ◽  
Todd B Marder

The 1:1 molecular complexes of octafluoronaphthalene (OFN) with fluorene (1) and with 9,10-dihydrophenanthrene (2) were prepared by cocrystallization of the components and characterized by single-crystal X-ray diffraction. The structure of 1 can be described as a mixed-stack or a laminar checkerboard motif of alternating OFN and fluorene molecules, whilst slanted mixed-stack, herringbone, and face-to-face heteromolecular dimer motifs can all be recognised in 2.Key words: single crystal, X-ray structure, π stacking, fluoroarene.


2011 ◽  
Vol 332-334 ◽  
pp. 1687-1690
Author(s):  
Xia Wang ◽  
Ming Qing Xing

Single crystal structures of M2Ni (SO4)2.XH2O (M=Na, X=4; M=K, NH4, Rb, Cs, X=6) were investigated using the single crystal X-ray diffraction method. They crystallize isotypic (space group P2 (1)/c). Many structure features exhibit regularity with the relative size of radius, such as a, b, c, V. But to ANSH, the regularity of average bond lengths of violets from others. Their optical transmission spectrums were recorded on PE-lambda 900 with performing wavelengths ranging from 200 to 1100 nm, they have the similar optical characters in tested wavelength range. This phenomenon arises from the electron transition of d orbits in the octahedral field. The similarity in optical spectrum is consistent with the comparability of structures. We also investigated the thermal-gravimetric quality of above single crystals under same experiment conditions. We found that the dehydration temperatures increase with increasing of radius of the M+ when M =K, Rb, Cs. When M=Na, the dehydration temperature (tdh) is above the others pronouncedly due to the specialty of structure. To NH4-, the so-called compound is also with exception of the regularity.


2016 ◽  
Vol 72 (11) ◽  
pp. 1536-1540
Author(s):  
Alessio Caruso ◽  
Benjamin Blair ◽  
Joseph M. Tanski

The two title compounds are analogs of 1-indanone that are substituted at the 6-position with chlorine and bromine. Although very similar in molecular structure, the crystal structures are not isomorphous and reveal that 6-chloroindan-1-one, C9H7ClO (I), and 6-bromoindan-1-one, C9H7BrO (II), exhibit unique intermolecular packing motifs. The molecules of the chloro analog (I) pack with a herringbone packing motif of C—H...O interactions, whereas the bromo derivative (II) packs with offset face-to-face π-stacking, C—H...O, C—H...Br and Br...O interactions. Compound (II) was refined as a two-component non-merohedral twin, BASF 0.0762 (5).


2017 ◽  
Vol 46 (35) ◽  
pp. 11860-11874 ◽  
Author(s):  
Yogendra Singh ◽  
Ram N. Patel ◽  
Yogendra Pratap Singh ◽  
Abhay K. Patel ◽  
Neetu Patel ◽  
...  

Two new copper(ii) complexes have been synthesized and characterized by single crystal X-ray diffraction.


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