Carbo‐biphenyls and Carbo‐terphenyls: Oligo(phenylene ethynylene) Ring Carbo‐mers

Chongwei, Z.; Albert, P.; Carine, D.; Brice, K.; Alix, S.; Valérie, M.; Remi, C., Angew. Chem. Int. Ed. 2018, 57, 5640-5644
Contributed by Steven Bacharach
Reposted from Computational Organic Chemistry with permission

Interesting 18 π-electron systems involving cyclooctadecanonenetriyne rings have been synthesized and examined by computations.¹ The mono-, di- and tri-C₁₈
ring compounds 1, 2, and 3 were prepared and the x-ray structure of 2 was obtained. The B3PW91/6-31G(d,p) optimized geometries of 1-3 and of the tetra ring 4 are shown in Figure 1.

1

2

3

4

Figure 1. B3PW91/6-31G(d,p) optimized geometries of 1-4.

Since the rings are composed of 18 π-electrons in the π-system perpendicular to the nearly planar ring, the natural question is to wonder if the ring is aromatic. The authors computed NICS(0) and NICS(1) values at the center of the C₁₈ rings. For all four compounds, both the NICS(0) and NICS(1) values are negative, ranging from -12.4 to -14.9 ppm, indicating that the rings are aromatic.

References

1) Chongwei, Z.; Albert, P.; Carine, D.; Brice, K.; Alix, S.; Valérie, M.; Remi, C., "Carbo‐biphenyls and Carbo‐terphenyls: Oligo(phenylene ethynylene) Ring Carbo‐mers." Angew. Chem. Int. Ed. 2018, 57, 5640-5644, DOI: 10.1002/anie.201713411.

InChIs

1: InChI=1S/C58H54/c1-3-5-7-9-11-17-27-49-37-41-55(51-29-19-13-20-30-51)45-47-57(53-33-23-15-24-34-53)43-39-50(28-18-12-10-8-6-4-2)40-44-58(54-35-25-16-26-36-54)48-46-56(42-38-49)52-31-21-14-22-32-52/h13-16,19-26,29-36H,3-12,17-18,27-28H2,1-2H3
InChIKey=KWXYBTWOEJBCQD-UHFFFAOYSA-N

2: InChI=1S/C102H74/c1-3-5-7-9-11-21-39-83-59-67-95(87-41-23-13-24-42-87)75-79-99(91-49-31-17-32-50-91)71-63-85(64-72-100(92-51-33-18-34-52-92)80-76-96(68-60-83)88-43-25-14-26-44-88)57-58-86-65-73-101(93-53-35-19-36-54-93)81-77-97(89-45-27-15-28-46-89)69-61-84(40-22-12-10-8-6-4-2)62-70-98(90-47-29-16-30-48-90)78-82-102(74-66-86)94-55-37-20-38-56-94/h13-20,23-38,41-56H,3-12,21-22,39-40H2,1-2H3
InChIKey=HHRPTZGYBIHFOL-UHFFFAOYSA-N

3: InChI=1S/C146H94/c1-3-5-7-9-11-25-51-117-81-93-135(123-53-27-13-28-54-123)105-109-139(127-61-35-17-36-62-127)97-85-119(86-98-140(128-63-37-18-38-64-128)110-106-136(94-82-117)124-55-29-14-30-56-124)77-79-121-89-101-143(131-69-43-21-44-70-131)113-115-145(133-73-47-23-48-74-133)103-91-122(92-104-146(134-75-49-24-50-76-134)116-114-144(102-90-121)132-71-45-22-46-72-132)80-78-120-87-99-141(129-65-39-19-40-66-129)111-107-137(125-57-31-15-32-58-125)95-83-118(52-26-12-10-8-6-4-2)84-96-138(126-59-33-16-34-60-126)108-112-142(100-88-120)130-67-41-20-42-68-130/h13-24,27-50,53-76H,3-12,25-26,51-52H2,1-2H3
InChIKey=WCBXPLIBHKYESX-UHFFFAOYSA-N

4: InChI=1S/C190H114/c1-3-5-7-9-11-29-63-151-103-119-175(159-65-31-13-32-66-159)135-139-179(163-73-39-17-40-74-163)123-107-153(108-124-180(164-75-41-18-42-76-164)140-136-176(120-104-151)160-67-33-14-34-68-160)97-99-155-111-127-183(167-81-47-21-48-82-167)143-147-187(171-89-55-25-56-90-171)131-115-157(116-132-188(172-91-57-26-58-92-172)148-144-184(128-112-155)168-83-49-22-50-84-168)101-102-158-117-133-189(173-93-59-27-60-94-173)149-145-185(169-85-51-23-52-86-169)129-113-156(114-130-186(170-87-53-24-54-88-170)146-150-190(134-118-158)174-95-61-28-62-96-174)100-98-154-109-125-181(165-77-43-19-44-78-165)141-137-177(161-69-35-15-36-70-161)121-105-152(64-30-12-10-8-6-4-2)106-122-178(162-71-37-16-38-72-162)138-142-182(126-110-154)166-79-45-20-46-80-166/h13-28,31-62,65-96H,3-12,29-30,63-64H2,1-2H3
InChIKey=LLVPDVPZEIYJGN-UHFFFAOYSA-N

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