Triphenylene-ethylammonium tetrachlorometallate salts: multicolumnar mesophases, thermochromism and Langmuir films

ARTICLE Please do no adjus ma gins Please do no adjus ma gins Recei ed 00 h Janua y 20xx, Accep ed 00 h Janua y 20xx DOI: 10.1039/x0xx00000x T iphenylene-e hylammonium Te achlo ome alla e sal s: Mul icolumna Mesophases, The moch omism and Langmui ilms† Ma ía Ba cenilla,a Ma ía Jesús Baena,a Be and Donnio,*,b Benoî Hein ich,b Lucía Gu ié ez,c Sil e io Coco,*,a and Pablo Espine .*,a This s udy epo s new mesomo phic benzyle hylammonium sal s con aining a 2,3,6,7,10-pen akis(dodecyloxy)-11- (hexyloxy) iphenylene uni and Cl- o [MCl4]2- (M = Cu, Ni, Co, Mn) as coun e ion. They show a ich columna polymesomo phism, cha ac e ized by pola ized op ical mic oscopy (POM), di e en ial scanning calo ime y (DSC), and small- and wide-angle X- ay sca e ing (S/WAXS). All he compounds sel -o ganize in o mul iseg ega ed s uc u es in he solid s a e and in he mesophases, wi h he al e na ion wi hin la ge supe la ices o iphenylene-con aining columns and benzylammonium chlo ide o e acho ome alla e agmen s. In e es ingly, he nickel de i a i e displays a con inuous and e e sible he moch omic beha io in he ange o 50-80 °C. Magne ic measu emen s and UV-Vis da a a di e en empe a u es, suppo changes in he coo dina ion sphe e o he Ni(II) a om om oc ahed al o e ahed al. Fu he mo e, hese sys ems o m s able and homogeneous Langmui ilms a he ai -wa e in e ace. These ilms ha e been success ully ans e ed on o solid subs a es gi ing ise o nanos uc u ed LB ilms wi h a clea ly de ined bilaye s uc u e in which each laye consis s o molecula columns aligned along he su ace. In oduc ion Building low-cos de ices wi h lexible and easily p ocessable componen s is a s ongly desi ed objec i e in so elec onic echnology. This equi es new unc ional ma e ials wi h p ede e mined physical p ope ies. A ep esen a i e case is ha o unc ional columna liquid c ys als wi h speci ic op ical, elec ic o magne ic p ope ies ha can be combined wi h he sup amolecula o ganiza ion and luidi y o he liquid c ys alline mesophases. 1 - 8 T iphenylene-based mesogens a e pa o a widely s udied subclass o columna liquid c ys als. 9 , 10 Thei p ope ies can be modula ed h ough ailo ing o he iphenylene co e wi h a a ie y o unc ional g oups, 11 - 15 including me al-o ganic complexes. 16 - 21 In his sense, we ha e epo ed mesomo phic me al-o ganic complexes con aining iphenylene moie ies, 22 - 24 whe e he luminescen p ope ies o he mesophase 25 and he cha ge mobili y along he columna s acking 26 , 27 a e modula ed by he me al agmen . The moch omic ma e ials a e also p omising unc ional ma e ials o mul iple applica ions, such as ene gy-sa ing windows, 28 , 29 empe a u e indica o s, 30 , 31 display ins umen s 32 o secu i y ma e ials. 33 They can be designed o a a ie y o ma e ials including liquid c ys als, 34 polyme s, 35 and me al- con aining complexes. 36 In he liquid c ys als ield, he he moch omic beha iou p oduced by chi al mesophases is well known and widely used o he p epa a ion o he moindica o s. The moch omic liquid c ys als based on non- chi al sys ems a e ela i ely sca ce and mainly co espond o columna me allomesogens, in which he colou change is a ibu ed o he a ia ion o he in e disc dis ance wi h empe a u e, o o phase ansi ions in he case o calami ic sys ems. 37 , 38 In non-mesogenic me al complexes, his beha iou is usually due o a change in ei he he c ys alline phase, he geome y o he me al cen e, o he numbe o sol en molecules in he s uc u e. 36 Looking o he moch omic liquid c ys als based on me al complexes ha can induce me al-cen ed he moch omism wi hou he need o chi al s uc u es, we ha e chosen o s udy iphenylene-e hylammonium sal s (TPh-NH 2 E + ) o po en ially he moch omic Cu(II), Ni(II), Co(II) and Mn(II) e achlo ome alla es. Fo ins ance, i is known ha (NE 2 H 2 ) 2 [NiCl 4 ] shows a e e sible he moch omic beha io . 40 Fu he mo e, hese designed molecula s uc u es, inspi ed by o he p e ious s uc u ally epo ed ma e ials, 23,26 made o a iphenylene uni connec ed o a benzylammonium sal ia an a. IU CINQUIMA/Química Ino gánica, Facul ad de Ciencias, Uni e sidad de Valladolid, 47071 Valladolid, Cas illa y León, Spain. E-mail; sil e io.coco@u a.es, espine @qi.u a.es b. Ins i u de Physique e Chimie des Ma é iaux de S asbou g (IPCMS), UMR 7504 (CNRS-Uni e si é de S asbou g), F-67034 S asbou g Cedex 2 (F ance). E-mail: be [email protected] a. c. Dep . Química Analí ica, Ins i u o de Nanociencia y Ma e iales de A agón (INMA), CSIC-Uni e sidad de Za agoza and Cibe -BBN, Za agoza 50018, Spain. † This wo k is dedica ed o hono P o esso Pe e M Mai lis, who has passed away a he age o 90 when he e ision o his pape was o be submi ed. Mai lis was an ou s anding and dedica ed man o science and a human example o all hose who had he p i ilege o wo k close him. We owe him much mo e han he wo d “me allomesogens”. Elec onic Supplemen a y In o ma ion (ESI) a ailable: [de ails o any supplemen a y in o ma ion a ailable should be included he e]. See DOI: 10.1039/x0xx00000x Jou nal o Ma e ials Chemis y C, 2022, 10, 9222. DOI: h ps://doi.o g/10.1039/D2TC01100J ARTICLE Jou nal Name 2 | J. Name., 2012, 00, 1-3 This jou nal is © The Royal Socie y o Chemis y 20xx Please do no adjus ma gins Please do no adjus ma gins alkyl space , we e expec ed o lead o he o ma ion o mul icolumna mesophases, as bo h immiscible species should phase sepa a e and be con ined in di e en egions in he mesophase. As an addi ional aspec o in e es , hese sys ems may o m s able Langmui ilms a he ai /wa e in e ace, which could be ans e ed e y e icien ly o glass subs a es o gi e Langmui -Blodge ilms wi h well-o de ed bilaye s uc u es. Resul s and discussion Syn hesis and Cha ac e iza ion The un epo ed iphenylene de i a i e [TPh-NH 2 E ]Cl ( 3 ) was p epa ed om he co esponding aldehyde as shown in Scheme 1. The e hylammonium e achlo ome alla e sal s ( 4-7 ) we e syn hesized by di ec eac ion o 3 wi h he co esponding me al chlo ide MCl 2 (Scheme 1) and isola ed as colou ed solids in 88-98% yield. Fo syn he ic and cha ac e iza ion de ails, see ESI. Scheme 1. Syn hesis o he Cl – and [MCl 4 ] 2– sal s o [TPhO-C 6 H 4 -CH 2 -NH 2 E ] + (3-7). i: a) E NH 2 , THF; b) NaBH 4 , THF + E OH. ii: HCl, CH 2 Cl 2 . iii: MCl 2 , CH 2 Cl 2 /E OH. The s uc u es o con en ional (R 2 NH 2 ) 2 [MCl 4 ] complexes (M = Cu, Ni, Mn, Co, R = alkyl) epo ed in he li e a u e can be aken as easonable models o 4 - 7 . In he solid s a e, hese s uc u es consis o an al e na ion o anionic me al halide laye s pa i ioned by a ays o ca ions. The ino ganic egions o he coope , 39 nickel, 40 and manganese 41 , 42 compounds consis o dis o ed MCl 6 oc ahed a ea u ing MCl 4 laye s o squa e plana me al cen es sha ing b idging chlo o ligands, and wo apical e minal Cl ligands on each me al cen e. 43 A a iance wi h hose, epo ed e ahed al [CoCl 4 ] 2- g oups we e ound in he cobal a e sal s. 44 Consis en wi h hese li e a u e da a, he IR spec a o he Cu, Mn and Ni sal s 4 , 5 , and 7 (Figu e 1) a e ypical o oc ahed al, polyme ic ma e ials con aining b idging halo-ligands, wi h an abso p ion a ca. 226 cm -1 . 40 In con as , he cobal sal 6 displays a single abso p ion a 282 cm -l , assigned o n (Co–Cl) in a e ahed al [CoCl 4 ] 2- anion. 44 Figu e 1. Fa -in a ed spec a o TPh-NH 2 E + sal s a 298 K (L = Cl – sal ; M = [MCl 4 ] 2– sal ). The elec onic spec a o he 4 - 7 TPh-NH 2 E + sal s in he solid s a e (di use e lec ance) a oom empe a u e display a spec al pa e n wi h abso p ion bands in he ange 240-400 nm, co esponding o he 2,3,6,7,10,11-hexaalkoxy iphenylene g oup (Figu e 2). 45 , 46 The cobal a e sal shows, in addi ion, an in ense abso p ion band a lowe ene gy assigned o an 4 A 2 → 4 T 1 ( 4 P) ansi ion in he e ahed al [CoCl 4 ] 2- g oup. 47 In con as , o he o he e achlo ome alla e de i a i es only b oad low-in ensi y abso p ion bands in he ange 400-480 nm a e obse ed, in acco dance wi h hei oc ahed al o dis o ed- oc ahed al coo dina ion geome ies (Figu e 2). 48 Figu e 2. UV-Vis di use e lec ance spec a o he TPh-NH 2 E + sal s in he solid s a e (di use e lec ance) a 298 K (L = Cl – sal ; M = [MCl 4 ] 2– sal ). The mal beha iou and sel -o ganiza ion p ope ies The mesomo phic p ope ies o [TPh-NH 2 E ]Cl ( 3 ) and he ou e achlo ome alla e sal s ( 4 - 7 ) ha e been s udied by pola ized op ical mic oscopy (POM), di e en ial scanning calo ime y (DSC), and small- and wide-angle X- ay sca e ing (S/WAXS). The op ical, he mal and he modynamic da a a e ga he ed in Table 1. Rep esen a i e mic opho og aphs a e shown in Figu e 3. The mesophase assignmen o Table 1 is based on he esul s o he S/WAXS s udies. Addi ional da a a e p o ided in he Elec onic Suppo ing In o ma ion. C H O OC6H12 RO RO RO OR OR TPhO HN TPhO H2N TPhO MCl4 2- M = Cu (4, 95 %), Ni (5, 88 %), Co (6, 96 %), Mn (7, 98 %) ii + Cl- H2N TPhO + 2 i R = C12H25 (1) (2), 89 % (3), 96 % iii = TPh Jou nal Name ARTICLE This jou nal is © The Royal Socie y o Chemis y 20xx J. Name., 2013, 00, 1-3 | 3 Please do no adjus ma gins Please do no adjus ma gins Table 1. Op ical, he mal, and he modynamic da a o he TPh-NH2E + sal s. Cpd T ansi iona Tb (°C) ∆Hb (kJ mol-1) (3) C → M M → Col ec Col ec → I 40.8 80.1 95.7 42.6 2.6 3.2 (4) C → M M → Col ec Col ec → I 43.4 99.7 116.1 102.4 2.7 2.8 (5) c C → M M → Col ec Col ec → I 44.6 99.7 120.4 108.3 2.7 6.0 (6) C → M M → Col ec Col ec → Colhex/Colsqu Colhex/Colsqu → I 43.6 103.7 126.5 139.9 95.7 3.2 1.8 1.8 (7) c C → M M → Col ec Col ec → Colhex/Colsqu Colhex/Colsqu → I 45.4 110.6 124.2 140.1 104.3 2.3 0.3 2.6 a C , c ys al phase; M: unknown mesophase wi h a la ge supe la ice; Col ec, ec angula columna mesophase; Colhex, hexagonal columna mesophase; Colsqu, squa e columna mesophase; I, iso opic liquid; mesophase assignmen based on S/WAXS s udies b Da a collec ed om he second hea ing DSC cycle. The ansi ion empe a u es a e gi en as peak onse s. c Scanning a e: 5 °C/min. All he compounds show good s abili y up o empe a u es abo e 200 °C (Figu es S12–S15), and display enan io opic mesophases, as deduced om he obse a ion o luid and bi e ingen op ical ex u es (Figu e 3 and Table 1). Ei he wo ( o 3 , 4 , 5 ) o h ee ( o 6 , 7 ) mesophases a e de ec ed be ween he mel ing and he clea ing poin in he DSC cycles, bo h in he hea ing and in he cooling, con i ming he polymesomo phism o hese compounds (Figu es S7-S11 in he Suppo ing In o ma ion). The ex u es obse ed by POM on cooling om he iso opic liquid, simila o all compounds, a e a p io i compa ible wi h he occu ence o columna mesophases. 26,34 Howe e , hei unambiguous exac iden i ica ion om he ex u es obse ed is no possible. Figu e 3. Op ical pola izing mic oscopy pho og aphs (x100, c ossed pola ize s) on cooling om he iso opic phase o : a) [TPh-NH 2 E ]Cl (3) a 87 °C; b) [TPh- NH 2 E ] 2 [CuCl 4 ] (4) a 109 °C; c) [TPh-NH 2 E ] 2 [NiCl 4 ] (5) a 112 °C. A mo e p ecise iden i ica ion o he liquid c ys alline mesophases was achie ed by S/WAXS. The pa e ns eco ded o all compounds in hei p is ine s a e and a a ious empe a u es (Figu es S16-S20, Tables 2 and S1 in ESI) con i m ha he complexes sel -o ganize in o mul iseg ega ed columna s uc u es, wi h he al e na ion wi hin la ge supe la ices o TPh-con aining columns and benzylammonium chlo ide o e acho ome alla e sal s (labelled as BzaS = Benzylamonium- Sal ) embedded in an alipha ic con inuum. The p is ine s a es a e cha ac e ized by he p esence o one sha p small-angle peak, se e al un esol ed di used signals o e he S/WAXS angula ange, and a sligh ly s uc u ed b oad signal in he wide- angle ange, co esponding o incomple ely mol en alipha ic chains, an indica ion o pa ially c ys allized solid s a e wi h s ill high le el o s uc u al diso de . On u he hea ing, he X- ay pa e ns a e sys ema ically ans o med, in ag eemen wi h he induc ion o a mo e long- ange sup amolecula o ganiza ion. Whils s ill e aining he single sha p small-angle e lec ion, one could obse e he de elopmen o he mid-angle b oad sca e ing signal, labelled D, in o a se o se e al no -well esol ed bu sha p e lec ions (Figu e 4 and S16-S20), and he spli ing o he b oad la ge-angle sca e ing in o wo di e en con ibu ions, namely: i) he s ong one a ca. 4.5-4.6 Å, co esponding o he undi e en ia ed liquid-like la e al dis ances be ween alipha ic chains and space s and benzylammonium-sal moie ies, h ch +h BzaS , espec i ely; and ii) he one a 3.5-3.6 Å, co esponding o he iphenylene uni s o hogonally s acked o e sho dis ances, h p . A his s age, he na u e and symme y o his mesophase, M, could un o una ely no be unambiguously esol ed, as oo many indexa ion solu ions we e compa ible wi h so ew no -so-well esol ed e lec ions. I could ne e heless co espond o a long- ange, likely 3D, p e-o ganized s uc u e o he mesophase o ming a highe empe a u e. The X- ay pa e ns we e sligh ly modi ied on u he hea ing, and all he sha p and s ong e lec ions could be indexed acco ding o a 2D ec angula symme y (Table S1). In he wide- angle pa , he spli signals h ch +h BzaS /h p o he p eceding M phase was ans o med in o a single b oad and ex ended wide- angle signal co esponding o he o e all me ging o all he a ious con ibu ions (h = h ch +h BzaS + h p ) (h p , is ha dly isible o compounds 3 and 7 , and has o ally disappea ed o he o he compounds, in ag eemen wi h he educ ion o he s acking dis ance o a ew iphenylene uni s only). As jus men ioned, in he small-angle ange, hey exhibi a se o se e al sha p small- angle e lec ions (hk) cha ac e izing he wo-dimensional a angemen o mesogenic columns sepa a ed in space by a mol en alipha ic con inuum. The p esence o he unde lying b oad signal a in e media e angula ange, D, was s ill de ec ed, as o he mesophase M, which was associa ed o he de elopmen o some local- ange supe s uc u e. Finally, as men ioned abo e, o he Co and Mn complexes an addi ional mesophase could be de ec ed be ween he ec angula phase and he iso opic liquid. In he wo cases, he only di e ence wi h he ec angula phase is he collapse o he mid-angle e lec ions in o he single b oad sca e ing signal, D, and he p esence o only one sha p small-angle e lec ion. In he ARTICLE Jou nal Name 4 | J. Name., 2012, 00, 1-3 This jou nal is © The Royal Socie y o Chemis y 20xx Please do no adjus ma gins Please do no adjus ma gins wide-angle, all signals om he chains, he BzaS and TPh uni s a e o e lapped in o an undi e en ia ed single b oad signal, h. On his basis, he mesophase could be assigned ei he as hexagonal (Col hex ) o as squa e (Col squ ) columna mesophase. In he iso opic liquid phase (Iso), he b oad small-angle signal D was ound o pe sis , which is due o some eminiscence o he nanoseg ega ion s ill occu ing a he local- ange le el be ween he TPh and he BzaS moie ies. The single b oad signal seen in he wide-angle ange o he Col hex/squ phase is associa ed o undi e en ia ed liquid-like con ibu ions o he chains, BzaS and TPh moie ies. Figu e 4. Rep esen a i e S/WAXS pa e ns o he compounds in he mesophase. hk indexa ion o he small-angle peaks; hch+hBzaS, undi e en ia ed liquid-like la e al dis ances be ween alipha ic chains and space s, and benzylammonium-sal moie ies, espec i ely; hp, iphenylene s acking o e sho dis ances; D, sho - ange co ela ed pe iodici y om he sup amolecula assembly. Fo 6, he signal canno be decon olu ed since he s acking signal (hp) is oo weak, i no unexis en ; i s heo e ical posi ion (shown in b acke s) is indica ed by he dashed a ow. The eme gence o columna mesophases wi h la ge supe la ice s uc u es, con aining se e al columns pe la ice (mul icolumna mesophases, see below), was hus con i med o all compounds by he p esence o se e al sha p, small-angle e lec ions, e ealing la ices wi h la ge dimensions, along wi h he modula ion o he e lec ions in ensi y dis ibu ion. These pa e ns also con i med he e icien seg ega ion be ween he a ious pa s, namely, he iphenylene discs, he BzaS species (Cl – o [MCl 4– ] anions) and he chains. As expec ed, he mesomo phism induc ion o his kind o compounds is s ongly d i en by he endency o he iphenylenes o s ack in o one- dimensional columns and o nanoseg ega e in space due o hei pe iphe al alkyl chains. Howe e , he BzaS agmen s a e also con ined in o sepa a e zones, and hei a angemen mus espec he a ious geome ical cons ain s and he mesophase symme y in each case. The e o e, hese sal s sel -assemble in la ge supe la ices o ec angula and hexagonal/squa e symme ies wi h he conce ed en anglemen o wo subne wo ks o se e al iphenylene-based columns and BzaS- based (me al-based) columns, espec i ely, each ypes being sepa a ed by he in ini e con inuum o mol en alkyl chains. As p e iously de eloped, 23,26 mo e in ima e de ails abou he espec i e o ganiza ion o he wo subse s o columns wi hin he supe la ices can be e ealed om he a io be ween he molecula olume (V mol ) and he la ice a ea (A, wi h Z = 2, o he ec angula symme y, and Z = 1 o hexagonal/squa e symme y), scaled by he o al numbe o ligands o complexes pe la ice, Z mol (Table 2). This le us o deduce he numbe o TPh- and BzaS-based columns pe la ice (Z col,TPh = Z mol ×n TPh/mol , Z col,BzaS = Z, espec i ely) by epea ing ial-e o es s and conside ing he mos logical solu ion in ag eemen wi h he symme y elemen s o he plana g oup, i.e. ec angula and hexagonal/squa e plana g oups (Table 2). This calcula ion also p o ides a alue o h TPh , he molecula slice hickness along he TPh-based columns (h TPh = (V mol /n TPh,mol )/(A/Z col,TPh )), which lies close o he alue o h p , consis en wi h a nea ly o hogonal s acking o he iphenylene discs in he columns. Fo he ec angula phases, a alue o 8 ( o he p ecu so 3 ) and 4 ( o he complexes 4-7) is deduced o Z mol , espec i ely, which gi es columna ec angula supe la ices con aining 8 TPh- and 2 BzaS-based columns. A plausible sup amolecula a angemen o he columns in he ec angula mesophase (Figu e 5) would consis o a s ack o ammonium/me al agmen s loca ed a he nodes o he ec angula la ice (co ne s and cen e, Z col,BzaS = 2), in e wined by a ne wo k o 8 discoidal columns (Z col,TPh ), hus espec ing he iphenylene-me al agmen s oichiome y, bo h sepa a ed by he alipha ic con inuum, in comple e ag eemen wi h he cen ed symme y and dimensions o he ec angula la ice, and he modula ed dis ibu ion o he in ensi ies o he highe o de e lec ions. As o he Col hex/squ phase o compounds 6 and 7 , hese calcula ions gi e 2 complexes, wha e e he symme y conside ed, ha indica es a sel -assembly made o 4 TPh- and 1 BzaS-based columns (Table 2). F om he S/WAXS pa e ns, i was no possible o disc imina e be ween a columna mesophase wi h hexagonal o squa e symme y (only he undamen al e lec ion is seen), so bo h mesophases a e equip obable. Thus, a possibili y o a anging he columns in he mesophase (Figu e 4) would consis o a s ack o me al agmen s loca ed a he co ne s o he hexagonal/squa e Jou nal Name ARTICLE This jou nal is © The Royal Socie y o Chemis y 20xx J. Name., 2013, 00, 1-3 | 5 Please do no adjus ma gins Please do no adjus ma gins la ice (Z col,BzaS = 1), in e wined by a ne wo k o 4 discoidal columns (Z col,TPh ) wi hin he la ice, also espec ing he iphenylene-me al agmen s oichiome y, bo h ypes o columns being sepa a ed by he alipha ic con inuum. The only di e ence, and his would be mo e in he a ou o he squa e la ice, is he es ima ion o h TPh , which gi es a alue o ca. 4.2- 4.3Å close o h (4.3Å, Table 2), conside ing he squa e symme y, whe eas his calcula ion gi es a alue o ca. 3.7Å o he hexagonal case. Table 2: S uc u al pa ame e s. Cpdsa T (°C) Phaseb (Z) 2D la ice pa ame e sc Vmold nBzaS/mole nTPh/mol hp [x]/h Zmol Zcol,BzaSg Zcol,TPh hTPhh 3 90 Col ec c2mm (Z = 2) a = 89.6(9); b = 65.6(7); g = 90°; A = 5890 Å2; a/b = 1.37 2541 0.94 1 1 3.6 [2]/4.5 8 2 8 3.45 4 110 Col ec c2mm (Z = 2) a = 91.0(8); b = 65.0(8); g = 90°; A = 5927 Å2; a/b = 1.40 5269 0.95 1 2 3.6 [2]/4.5 4 2 8 3.56 5 110 Col ec c2mm (Z = 2) a = 90.4(7); b = 65.7(3); g = 90°; A = 5947 Å2; a/b = 1.38 5268 0.95 1 2 3.6 [2]/4.5 4 2 8 3.54 6 115 Col ec c2mm (Z = 2) a = 91.3(0); b = 66.2(5); g = 90°; A = 6049 Å2; a/b = 1.38 5285 0.94 1 2 3.5 [2]/4.5 4 2 8 3.50 6 135 Colhex p6mm (Z = 1) a = b = 57.6; g = 120° A = 2871 Å2 5352 0.93 1 2 -/4.3 2 1 4 3.73 Colsqu p4mm (Z = 1) a = b = 49.9; g = 90° A = 2490 Å2 5352 0.93 1 2 -/4.3 2 1 4 4.3 7 115 Col ec c2mm (Z = 2) a = 92.2(5); b = 65.5(5); g = 90°; A = 6047 Å2; a/b = 1.41 5310 0.94 1 2 3.6 [2]/4.5 4 2 8 3.51 7 135 Colhex p6mm (Z = 1) a = b = 58.0; g = 120°; A = 2917 Å2 5360 0.93 1 2 -/4.3 2 1 4 3.68 Colsqu p4mm (Z = 1) a = b = 50.3; g = 90° A = 2530 Å2 5360 0.93 1 2 -/4.3 2 1 4 4.2 aT: empe a u e o he measu emen ; bCol ec, Colhex/squ: ec angula and hexagonal/squa e columna mesophases and highes possible symme y, Z: numbe o mo i s (molecula agg ega es) pe la ice; ca, b, g, A = a×b×sing, Z, a/b: la ice pa ame e s, la ice a ea and la ice pa ame e a io; dVmol (Å3), (g/cm3): calcula ed molecula olume and densi y; enBzaS/mol, nTPh/mol: numbe o benzylammonium/anion uni s and numbe o TPh uni s pe molecule (s oichiome y); hp, [x]: a e age p-s acking dis ance (Å) and associa ed co ela ion leng h om wide-angle sca e ing analysis (nm) calcula ed using he Sche e equa ion wi h shape ac o K = 0.9; 49 h: undi e en ia ed liquid-like con ibu ions o he chains, BzaS and TPh moie ies; Zmol: numbe o molecules pe la ice; gZcol,BzaS = Z: numbe o benzylammonium/anion columns pe la ice; Zcol,Tph = Zmol×nTPh/mol: numbe o TPh columns pe la ice; hhTPh = (Vmol/nTPh,mol)/(A/Zcol,TPh): molecula slice hickness along TPh columns (Å). ARTICLE Jou nal Name 6 | J. Name., 2012, 00, 1-3 This jou nal is © The Royal Socie y o Chemis y 20xx Please do no adjus ma gins Please do no adjus ma gins Figu e 5. Illus a ion o he p oposed 2D packing o he Col ec mesophase (c2mm symme y, and o he Colsqu mesophase (p4mm symme y), and o he Colhex mesophase (p6mm symme y). The pink disks co espond o TP-based columns, and he g een pe als o BzaS–based agg ega es; he alipha ic chains, occupying he whi e a eas, a e no shown o cla i y. The moch omic beha iou The nickel complex 5 is g een a oom empe a u e and swi ches o a bluish colou upon hea ing a abou 60 °C (Figu e 6). The compound shows e e sible he moch omic beha iou and, upon cooling o oom empe a u e, i e u ns g adually o i s o iginal g een colou . Figu e 6. Pho og aphs o he moch omic complex [TPh-NH2E ]2[NiCl4] (5) a di e en empe a u es. In o de o unde s and his colou change, he elec onic spec a o a d op-cas ilm o 5 we e eco ded a di e en empe a u es (Figu e 7). Figu e 7. Elec onic spec um o [TPh-NH2E ]2[NiCl4] (5) a 35 °C. Inse : spec al changes p oduced upon a ying he empe a u e. As discussed in he syn hesis and cha ac e iza ion sec ion, be o e hea ing he elec onic spec um o 5 is domina ed by abso p ion bands in he ange 240-400 nm, co esponding o he 2,3,6,7,10,11-hexaalkoxy iphenylene g oup, which p ac ically o e lap he weak abso p ion band ( 3 A 2g(F) → 3 T 1g(P) ansi ion) co esponding o oc ahed ally coo dina ed nickel. When he sample is hea ed abo e 45 °C, a double abso p ion band appea s, wi h maxima a 658 nm and 711 nm, which is ypical o he blue e ahed al [NiC1 4 ] 2- complex anion ( 3 T 1(F) → 3 T 1(P) ansi ion). 40,48 The e o e, he he moch omic phase ansi ion o he complex is assigned o he coo dina ion change o Ni(II) om oc ahed al o dis o ed-oc ahed al o e ahed al, as epo ed o ela ed non-mesogenic complexes in he solid s a e. 48, 50 Acco ding o he plo o abso bance s empe a u e (Figu e 8), he ansi ion occu s be ween 50 and 80 °C. Thus, he he moch omic ansi ion s a s and de elops along he mel ing p ocess. Figu e 8. Abso bance change a 𝜆 = 650 nm and 𝜆 = 700 nm as a unc ion o empe a u e. Magne iza ion measu emen s o he nickel compound a di e en empe a u es we e pe o med o assess he changes in magne ic p ope ies associa ed o he he moch omic ans o ma ion. The esul ing ield dependen magne iza ion cu es a e shown in Figu e 9. Figu e 9. Field dependen magne iza ion cu e o he nickel compound (5) a di e en empe a u es. All he magne iza ion cu es (Figu e 8) show an o e all simila pa e n, in which wo di e en magne ic con ibu ions a e obse ed. In e es ingly, when looking in o de ail, he ield dependen magne iza ion cu es a empe a u es below he Jou nal Name ARTICLE This jou nal is © The Royal Socie y o Chemis y 20xx J. Name., 2013, 00, 1-3 | 7 Please do no adjus ma gins Please do no adjus ma gins he moch omic ans o ma ion (3 and 27 ºC) a e di e en om hose eco ded a highe empe a u es (77 and 100 ºC), in ag eemen wi h he phase ansi ion occu ing be ween 50 and 80 °C. In all cases, in he low- ield egime obse ed in he inse o Figu e 8, a hys e esis loop wi h non-negligible coe ci i y was eco ded, indica ing e o- o e imagne ic in e ac ion be ween he Ni(II) a oms. In addi ion o his magne ic con ibu ion, a clea pa amagne ic beha iou is obse ed a highe ields, e ealed by he inc ease o he magne iza ion as he magne ic ield inc eased, wi hou any sign o sa u a ion. These esul s indica ed he co-exis ence o wo ypes o en i onmen s o he Ni a oms wi hin he ma e ial s uc u e. This ac is in acco dance wi h he X- ay da a discussed abo e: i) he pa ially c ys alline na u e o he solid phase and i s high le el o s uc u al diso de ; and ii) he pe sis ence in he mesophases o some local- ange supe s uc u e de ec ed in he solid s a e. Consequen ly, he e o- o e imagne ic con ibu ion can be assigned o he c ys al s uc u e o his ype o compound, whe e dis o ed Ni II Cl 6 oc ahed a a e sha ing b idging chlo o ligands. Howe e , he species con ibu ing o he pa amagne ic beha iou would be di e en depending on he empe a u e. A empe a u es abo e he mo opic ansi ion, he o ma ion o e ahed al e achlo onickela e anions explains he p esence o a pa amagne ic signal. Howe e , a lowe empe a u es, whe e his anion was no spec oscopically obse ed, he pa amagne ic con ibu ion should be associa ed wi h he non-c ys alline solid ac ion, in which long- ange o de ing will no occu as in he c ys alline ac ion. Langmui ilms Conside ing he amphiphilic na u e o he mesomo phic TPh- NH 2 E + sal s, we decided o s udy hei abili y o o m 2D nanos uc u es a he ai -wa e in e ace (Langmui ilms). Compounds [TPh-NH 2 E ]Cl ( 3 ) and [TPh-NH 2 E ] 2 [NiCl 4 ] ( 5 ) we e chosen as ep esen a i e sal s o his s udy. Bo h compounds o m monolaye ilms unde comp ession. Figu e 10 shows he su ace p essu e s. mean molecula a ea (SP-A) ob ained a 20 ± 1 °C, as well as he a ia ion o he ecip ocal o he comp essibili y (1/ 𝛽 ). 51 , 52 Figu e 10. SP–A iso he ms and 1/ 𝛽 –A plo o compounds 3 and 5. Table: Molecula occupied a eas a di e en phases and collapse p essu e o he Langmui ilms. LC = liquid condensed phase. Bo h monolaye ilms unde go a phase ansi ion be ween wo liquid condensed (LC) phases, deno ed by a minimum in 1/ 𝛽 which coincides wi h he sligh in lec ion obse ed in he iso he m a 20–30 mN/m. The collapse is eached a high su ace p essu es ( ≈ 50 mN/m), e ealing a good ancho ing o he ionic heads o he subphase. In addi ion, he pla eau ha appea s jus a e he collapse deno es he esis ance o he monolaye espec o he ans o ma ion in o a 3D phase. 53 In good ag eemen wi h i s double con en in TPh moie ies, he o mula uni o 5 occupies wice he a ea o ha o 3 . Howe e , he molecula a ea pe iphenylene g oup is la ge o 3 han o 5 despi e he bigge olume o he [NiCl 4 ] 2− anion. This is mos likely due o he inc ease in he ionic cha ge in [NiCl 4 ] 2− wi h espec o Cl − which enhances he anion-ca ion a ac ions, inc easing he ilm cohesion. The ilms s a o be o med wi h molecula a eas pe iphenylene o 127 ± 5 Å 2 (A onse ) and each ex apola ed o ze o mean molecula a eas (A e ) o 117 ± 4 Å 2 in he i s s ep o he iso he m. These molecula a eas oge he wi h he 1/ 𝛽 alues indica e ha he loa ing ilms o 3 and 5 a e in a liquid condensed phase LC1 whe e he TPh moie ies lay edge-on espec o he subphase. 54 , 55 , 56 On u he comp ession, he LC1 phase e ol es o ano he condensed bu less igid phase LC2, whe e he ex apola ed a eas a e equal o sligh ly smalle han hose in LC1, (see Figu e 10). This beha iou is unlike ha epo ed o he TPh-imidazolium o py idinium sal s, 55 whe e he monolaye i s ly shows a liquid expanded (LE) phase, wi h he iphenylenes lying la on he subphase, and hen eaches a mo e igid phase, bu no LC, wi h he iphenylenes s acked edge-on. This di e en beha iou may be ela ed wi h he ac ha he longe chain leng h and he smalle size o he ca ionic heads in ou compounds enhance he magni ude o he a ac i e in e ac ions o e he disagg ega ion powe o he wa e . Moni o ing o he comp ession p ocess by B ews e 's angle mic oscopy (BAM) (Figu es S21 and S22 in ESI) shows ha be o e comp ession, 3 and 5 exhibi i egula pa ches o condensed monolaye s, in acco dance wi h he high endency o iphenylene g oups o sel -assembling h ough 𝜋 - '𝜋 in e molecula in e ac ions. Thus, he comp ession p ocess should s a wi h agg ega es whose s uc u e mos likely consis s o columns o ca ions sandwiching a cen al egion o anions. As he p essu e inc eases (1 < 𝜋 < 20 mN/m), he app oxima ion o he agg ega es leads o he o ma ion o a condensed monolaye (LC1) whe e he molecula a angemen is, as p e iously discussed, edge-on ype wi h he iphenylene g oups a anged in columns pa allel o he subphase (Scheme 2). A highe p essu es (20 < 𝜋 < 50 mN/m), he compac ion o he monolaye and he consequen inc ease o he epulsion be ween ions p oduces he phase ansi ion om LC1 o LC2. BAM images o bo h phases show ha he monolaye is cons i u ed by di e en domains, which should be due o di e en domain o ien a ions. 53 No di e ences could be app ecia ed a he phase ansi ion bu an inc ease in b igh ness, which is usually ela ed o a mo e dense packing as well as o an inc ease in he monolaye hickness. These ARTICLE Jou nal Name 8 | J. Name., 2012, 00, 1-3 This jou nal is © The Royal Socie y o Chemis y 20xx Please do no adjus ma gins Please do no adjus ma gins obse a ions along wi h he ac ha he ex apola ed a eas in bo h phases do no display signi ican di e ences, sugges ha LC1 and LC2 mainly di e in he molecula o ien a ion o he TPh g oup wi h espec o he aqueous subphase. We p opose ha he TPh agmen s o a e and only he ionic g oups a e ancho ed o he subphase in LC2, leading o columna molecula a angemen s as depic ed in Scheme 2b. Scheme 2. P oposed columna a angemen a he ai -wa e in e ace co esponding o LC1 phase (a) and LC2 phase (b) adap ed o compound 5. Finally, o ma ion o 3D s uc u es (b igh e ical lines) was no obse ed un il o e aking he p essu e o collapse, hus co obo a ing he abo e-men ioned esis ance o he monolaye o ha ans o ma ion. Langmui -Blodge ilms Langmui ilms o 3 and 5 we e ans e ed o glass subs a es a wo di e en p essu es co esponding o LC2 (SP = 35 mN/m) and LC1 (SP = 15 mN/m) phases o build up Langmui Blodge (LB) ilms. Good Y- and Z- ype deposi ions we e achie ed, wi h ans e a es nea o he uni y, using hyd ophobic and hyd ophilic glasses espec i ely. To he bes o ou knowledge, he e a e no examples epo ed o Z- ype LB ilms om disco ic amphiphiles. 51,52,56, 57 , 58 , 59 . The ans e sal s uc u e o Z and Y- ype mul ilaye LB ilms was s udied by means o low-angle X- ay di ac ion. The di ac og ams co esponding o bo h ype o LB ilms buil a a cons an comp ession o 35 mN/m a e depic ed in Figu e 11. All o hem show h ee di ac ion peaks co esponding o (00l) planes, as well as se e al se s o Kiessig inges. This means ha he LB ilms ha e a pe iodic laye ed s uc u e wi h a small ugosi y. 60 A 15 mN/m, simila bilaye ed s uc u es ha e been ob ained, bu wi h smalle laye hickness (di ac og ams in ESI), con i ming ha he hickness o he monolaye inc eases on passing om LC1 o LC2 phase, as abo e sugges ed. Table 3 collec s he expe imen al plana dis ances and he mean laye hickness o each ilm. Figu e 11. Low-angle X- ay di ac og ams o he LB ilms o 3 and 5. Table 3. Low-angle XRD da a o he LB ilms o 3 and 5. All alues in Å. 3 5 Y- ype deposi ion a LC2 a d(00l) c 61.2 63.5 Laye hickness d 32.9 34.3 Z- ype deposi ion a LC2 b d(00l) 57.6 59.1 Laye hickness 53.5 53.5 Z- ype deposi ion a LC1 b d(00l) 53.1 54.4 Laye hickness 45.3 45.9 (a) Subs a e = hyd ophobized glass. (b) Subs a e = hyd ophilic glass. (c) Plana dis ances d(00l) ha e been calcula ed by a e aging he co esponding alues o each di ac ion peak. (d) The ilm hickness, , was calcula ed om he pe iodici y o he Kiessig inges subs i u ing he slope a o he g aph senθn/n in he o mula = λ/2a.60 The mean single laye hickness was calcula ed om he a e /numbe o ans e ed monolaye s. I is wo h no ing ha , independen o he deposi ion ype, all he di ac og ams display a simila pa e n, which is consis en wi h analogous bilaye s uc u es. A bilaye s uc u e upon Y- deposi ion is he expec ed esul . Howe e , upon Z-deposi ion, he o ma ion o a bilaye should equi e a eo ganiza ion o he deposi ed monolaye , as has been epo ed o LB ilms o a y acids 61 , 62 , 63 o phospholipids. 64 Thus, i is plausible ha he ups oke- ans e ed monolaye unde goes o e u ning du ing he subsequen imme sion, acqui ing a mo e s able bilaye ed s uc u e wi h a new hyd ophilic su ace p one o adhe e he ollowing monolaye a ups oke. Conclusions This s udy shows he ma ked endency o hese iphenylene- benzyle hylamonium de i a i es o sel -o ganize in o mul iseg ega ed s uc u es. S uc u al s udies suppo he nanoseg ega ion o iphenylene columns and benzylammonium chlo ide o e acho ome alla e sal moie ies, leading o mul icolumna sys ems, bo h in he solid s a e and in he mesophases. The he mal, op ical and magne ic p ope ies o hese ma e ials a e easily modula ed by he na u e o he anion. The in oduc ion o he e achlo onickela e g oup leads o he combina ion o mesomo phism and he moch omism in he sys em. This Jou nal Name ARTICLE This jou nal is © The Royal Socie y o Chemis y 20xx J. Name., 2013, 00, 1-3 | 9 Please do no adjus ma gins Please do no adjus ma gins compound shows isually a e e sible he moch omic beha iou , ligh -g een a oom empe a u e and blue a 70 °C, which was s udied wi h spec oscopical and magne iza ion measu emen s. The he moch omism in his compound implies a coo dina ion change o he nickel(II) cen e, om oc ahed al o e ahed al, which is no simple. The magne iza ion measu emen s a di e en empe a u es e eal he co- exis ence, in he condi ions o he measu emen s, o wo ypes o con ibu ions o he Ni(II) a oms in he ma e ial, one co esponding o e o- o e imagne ic in e ac ions oge he wi h a pa amagne ic beha iou ha changes abo e he mo opic ansi ion. In addi ion, hese compounds sel - assemble in o nanos uc u ed LB ilms wi h a well-de ined bilaye ed s uc u e whe e each laye is cons i u ed by he alignmen o molecula columns along he su ace. These esul s a e in e es ing o u u e ailo ing o me al- o ganic liquid c ys als combining he moch omic and magne ic esponse. Au ho Con ibu ions The au ho s ha e con ibu ed equally o he pape . Con lic s o in e es The e a e no con lic s o decla e. Suppo ing in o ma ion Ma e ials and me hods, ull de ails o syn he ic me hods, spec oscopic and analy ical da a o he new compounds, DSC he mog ams and X- ay di ac ion pa e ns no included in he ex . Acknowledgmen s This wo k was sponso ed by he Minis e io de Ciencia e Inno ación (P ojec PID2020-118547GB-I00) and he Jun a de Cas illa y León (P ojec VA224P20). M. B. hanks he Jun a de Cas illa y León o a PhD g an . BD and BH hank CNRS and he Uni e si y o S asbou g o suppo .