Variation of Spin-Transition Temperature in the Iron(III) Complex Induced by Different Compositions of the Crystallization Solvent

Va ia ion o Spin-T ansi ion Tempe a u e in he I on(III) Complex Induced by Di e en Composi ions o he C ys alliza ion Sol en Published as pa o a C ys al G ow h and Design i ual special issue on Molecula Magne s and Swi chable Magne ic Ma e ials I an Nemec,*Lucie Ko ásko á, and Rado an He chel* Ci e This: C ys . G ow h Des. 2023, 23, 1323−1329 Read Online ACCESS Me ics & Mo e A icle Recommenda ions * sı Suppo ing In o ma ion ABSTRACT: We c ys allized he Schi -base i on(III) spin- c osso e complex [Fe(3,5Cl-L5)(NCSe)] om di e en wo- componen sol en mix u es con aining me hanol and chlo o o m (Φ=V(CH3OH)/V(sol en ) = 0.05, 0.25, 0.50, 0.83, and 1.00). The ob ained c ys alline p oduc s we e cha ac e ized by X- ay di ac ion, and i was con i med ha hey a e all composed o he same c ys alline phase, and hey do no con ain any c ys al sol en . Howe e , signi ican di e ences in magne ic p ope ies we e obse ed, and he mal hys e esis changed om (in K) 121T↓ and 134T↑ o Φ= 0.05 and 0.25, down o 72T↓and 96T↑ o Φ= 1.00. The c ys al s uc u es o he low-spin and high-spin phases we e s udied heo e ically and expe imen ally. The unabili y o he spin-c osso e (SCO) beha io is an impo an assump ion o e sa ile applica ions o SCO ma e ials. Bene icially, SCO pa ame e s such as he mal hys e esis wid h, ansi ion empe a u e (T1/2), coope a i i y deg ee, cu e ab up ness, and comple eness can be manipu- la ed by sample modi ica ions. The e ec o he p esence 1−3 and loss 4 o a sol en molecule in he la ice, he selec ion o an anion, 5,6 as well as he choice o a side subs i uen 6−8 a e well- known s a egies o modi ying he SCO beha io . Also, me al dilu ion ep esen s a sophis ica ed app oach o modi ica ion o he SCO beha io and obse ing o he coope a i i y deg ee and ansi ion empe a u e o SCO ma e ials. The SCO beha io can be also uned by a pos syn he ic modi ica ion as was mani es ed by solid s a e pe o med anion me a hesis. 9 Ou ongoing in e es in he magne ic beha io o Fe(III) complexes wi h pen aden a e Schi base ligands has b ough ema kable esul s on dis inc magne ic beha io s o polymo phs wi hin his class o compounds, 10 o hyd ogen bonding induced modi ica ion o T1/2. 11 Recen ly, a new epo on SCO wi h b oad he mal hys e esis obse ed o an Fe(III) complex wi h a pen aden a e Schi base ligand H23,5Cl-L5 (N,N′-bis(1-hyd oxy-3,5-dichlo o-2-benzyliden)-1,6-diamino- 4-azahexane) has been epo ed by Renz e al. which na u ally caugh ou a en ion. 12 Complex [Fe(3,5-Cl-L5)(NCSe)] (1) exhibi s he mally induced SCO wi h 24 K wide he mal hys e esis (T1/2 = 99↓and 129↑K). F om he compa ison o he low-spin (LS, S= 1/2) and high-spin (HS, S= 5/2) c ys al s uc u es, i is appa en ha eo ganiza ion o nonco alen in e ac ions (H···Cl and Cl···Cl) happens upon spin ansi ion. This, i signi ican , could explain he obse a ion o he wide he mal hys e esis. In he o iginal epo , 12 he au ho s did no in es iga e his possibili y in g ea e de ail, and he e o e, ou o iginal mo i a ion o s udying his sys em was o ex ensi ely heo e ically and expe imen ally in es iga e he LS and HS c ys al s uc u es o 1. Fo he p epa a ion o 1we used a p ocedu e simila o ha in he o iginal epo , 12 bu ins ead o an ul asonic ba h we used a s anda d magne ic s i e . The eac ion be ween [Fe(3,5-Cl-L5)Cl] and KNCSe in pu e me hanol led o p ecipi a ion o a b own mic oc ys alline powde , which was il e ed o using a pape il e . Fo he p epa a ion o he single-c ys als sui able o X- ay di ac ion expe imen s we used he emaining mo he liquo which was c ys allized iso he mally. A e se e al days hin needle-like c ys als we e ob ained. Fi s , we collec ed he di ac ion da a o he HS s a e (150 K), and hen we a emp ed o measu e he LS s a e c ys al s uc u e a 90 K as was done in he o iginal epo . 12 To ou su p ise, he measu emen e ealed he c ys al s uc u e wi h he e y same me al−ligand bond leng hs and uni cell pa ame e s as was obse ed o he HS phase. Ob iously, his Recei ed: Decembe 1, 2022 Re ised: Feb ua y 14, 2023 Published: Feb ua y 16, 2023 Communica ionpubs.acs.o g/c ys al © 2023 Ame ican Chemical Socie y 1323 h ps://doi.o g/10.1021/acs.cgd.2c01411 C ys . G ow h Des. 2023, 23, 1323−1329 Downloaded ia BRNO UNIV OF TECHNOLOGY on Janua y 16, 2024 a 10:37:20 (UTC). See h ps://pubs.acs.o g/sha ingguidelines o op ions on how o legi ima ely sha e published a icles. did no ma ch he p e iously epo ed magne ic p ope ies. 12 The e o e, we measu ed he empe a u e dependence o he magne ic momen (μe /μB) o wo ob ained ac ions, needle- like c ys als (1_Φ1) and mic oc ys alline powde p ecipi a e (1_Φ1p). The measu emen s con i med he p esence o SCO wi h he mal hys e esis o bo h ba ches; howe e , he c i ical empe a u es and p o iles o magne ic unc ions we e di e en (Figu e 1). The 1_Φ1ba ch exhibi ed much lowe T1/2 (72↓ and 96↑K, ΔT= 24 K) han 1_Φ1_p (106↓and 129↑K, ΔT = 23 K, Figu e 1). Powde X- ay di ac ion undoub edly con i med ha bo h samples we e he same c ys allog aphic phase iden ical o he HS s uc u e o 1(Suppo ing In o ma ion, Figu e S6−S7). Inspi ed by his in iguing inconsis ency, we in es iga ed his phenomenon in g ea e de ail. F om magne ic measu emen s i is appa en ha he low T1/2 was obse ed o he ba ch composed o c ys als which g ew mo e han 5 days, whe eas he high T1/2 was obse ed o he p ecipi a e. The e o e, one o he es ed hypo heses was ha di e en c i ical empe a u es we e ela ed o he c ys allini y o he samples, which is ela ed o he ime o he c ys alliza ion. In an a emp o p epa e c ys als, whose c ys alliza ion spans di e en ime pe iods, we modi ied he composi ion o c ys alliza ion solu ions om pu e CH3OH o solu ions wi h a g owing po ion o CHCl3. CHCl3 was chosen as he second sol en because i dissol es 1 e y well; i does no en e he c ys al s uc u e o 1(does no o m a sol a e) and has a simila boiling empe a u e as CH3OH. The e o e, i could be expec ed ha he c ys alliza ion o 1will be go e ned by slow e apo a ion o he sol en mix u e. This mix u e g adually loses sligh ly mo e CHCl3 han CH3OH molecules (because o highe apo p essu e o CHCl3), and hus he solubili y o 1should be con inuously dec easing. Fou di e en c ys alliza ion mix u es wi h a di e en olume ac ion Φo CH3OH we e p epa ed (Φ= 0.83, 0.50, 0.25 and 0.05), and he co esponding c ys alline samples (1_Φ0.83, 1_Φ0.50,1_Φ0.25,1_Φ0.05) we e ob ained. In he case o he solu ions wi h Φ> 0.5 also mic oc ys alline p ecipi a es 1_Φ0.83p (besides al eady p epa ed 1_Φ1_p) we e ob ained and we e included in o his s udy. The pu i y o all he p epa ed samples was con i med by X- ay powde di ac ion. I mus be no ed ha in he case o one o he p ecipi a es (1_Φ1_p), he p esence o KCl impu i y was de ec ed as his is a side p oduc o he ligand me a hesis (Cl−ligand was subs i u ed by KNCSe). We decided no o wash he p ecipi a es wi h wa e (which would dissol e he impu i y), because i would in oduce a hi d sol en in o he s udied sys em. Fu he mo e, he p esence o he diamagne ic KCl should no a ec he SCO empe a u es. 1c ys allizes as e y hin needle-shaped c ys als. The symme y o he c ys als is monoclinic wi h he P21/nspace g oup (see Suppo ing In o ma ion, Table S1). The c ys al s uc u es o LS and HS phases we e well desc ibed in he o iginal epo , 12 and we will no add a new s uc u al desc ip ion he e. The bes quali y c ys als we e ob ained o he ba ch 1_Φ0.25. Again, we op ed o measu e he LS and HS c ys al s uc u es using a selec ed single c ys al om his ba ch. We moni o ed SCO using di ac ion me hods. The e o e, we s a ed he single c ys al X- ay di ac ion expe imen s a 140 K, and we collec ed se s o di ac ion da a a selec ed empe a u es on cooling and also on hea ing. A 116 K (on cooling), a d ama ic change in he quali y o di ac ions occu ed as his was he T1/2↓ empe a u e. The c ys al s uc u e o 1_Φ0.25@↓116K shows me al−ligand (ML) bond leng hs signi ican ly sho e (Table S2) han obse ed a highe empe a u es and in e y good ag eemen wi h he LS s uc u e o 1 epo ed in he o iginal pape . 12 Upon u he cooling (down o 108 K), nei he he M−L bond leng hs no he uni cell pa ame e s changed signi ican ly, and he e o e, we can conclude ha he ull HS →LS spin con e sion occu ed be ween 116 and 117 K (Figu e 2). Upon hea ing, we de ec ed he LS →HS ansi ion be ween 133 (LS) and 135 K (HS s uc u e), whe eas we we e no able o ge easonable da a om he measu emen a 134 K. We a emp ed o also measu e ano he SCO he mal cycle, bu he c ys al c acked upon ano he cooling. He e, we may conclude ha he single c ys al X- ay di ac ion measu emen s con i med ha 1_Φ0.25 exhibi s he mally induced SCO wi h hys e esis wide 18 K (i we assume T1/2↑ o be 134 K). This is no in ag eemen wi h he magne ic da a epo ed in he o iginal Figu e 1. Tempe a u e dependence o μe /μB o 1_Φ1and 1_Φ1p. Figu e 2. Tempe a u e dependence o μe /μB o 1_Φ0.25 ( op) and he empe a u e dependence o he selec ed uni cell pa ame e s as de e mined om he single c ys al X- ay di ac ion expe imen o 1_Φ0.25 (bo om). C ys al G ow h & Design pubs.acs.o g/c ys al Communica ion h ps://doi.o g/10.1021/acs.cgd.2c01411 C ys . G ow h Des. 2023, 23, 1323−1329 1324 pape , 12 bu i is also no in good ag eemen wi h he magne ic da a measu ed o 1_Φ1p. O no e he e is ha he coo dina es o he non-hyd ogen a oms in he HS c ys al s uc u e o 1_Φ1(a 90 K) a e almos iden ical wi h hose de e mined o 1_Φ0.25 (a 130 K, see Suppo ing In o ma ion, Figu e S1) and hus, he di e ence in T1/2 canno be assigned o changes in he c ys al s uc u es. We pe o med magne ic measu emen s o all he p epa ed ba ches. The esul s showed ha all he samples show he mally induced spin c osso e (Figu e S2 and Figu e S3). Rema kably, i is ob ious ha he ba ches p epa ed om he mix u e wi h he la ges con en o me hanol showed hys e e ic loops shi ed o lowe empe a u es, whe eas he ba ches om he highe CHCl3con en had hys e e ic loops shi ed o highe empe a u es (Figu e S2). The shi o hys e e ic loops is obse able also be ween 1_Φ0.83 and 1_Φ1; howe e , he da a o hei p ecipi a es 1_Φ0.83p and 1_Φ1p did no show a signi ican di e ence in T1/2 (Figu e S3). The hys e e ic loops o he ba ches wi h he highes CHCl3con en (1_Φ0.25 and 1_Φ0.05) a e e y simila , and hey exhibi he highes T1/2. The magne ic beha io o 1_Φ0.25 i s he empe a u e dependence o he uni cell pa ame e s a he well (Figu e 2). The obse ed beha io is ep oducible. The magne ic da a we e analyzed by using an Ising-like model (ISM) wi h Gaussian dis ibu ion o he coope a i i y pa ame e de i ed by Boca e al. 13 Wi hin he ISM de ined by he Hamil onian =H 2 (1) he ansi ion be ween wo spin s a es, σ=−1 o LS and σ= +1 o HS s a es, is go e ned by he ene gy di e ence be ween HS and LS s a es (Δ) and he coope a i eness o he sys em (Γ). Such a model can be modi ied o also include he dis ibu ion o he coope a i i y pa ame e Γin o de o deal wi h he impe ec ions o he c ys alline/powde samples by a ying he s anda d de ia ion pa ame e σo he Gaussian dis ibu ion unc ion. The main ad an age o such a model is i s abili y o ep oduce he slope o he hys e esis loops, and hence be e ag eemen wi h he expe imen al da a can be achie ed. Thus, he magne ic da a we e i ed by a ying Δ,Γ, e , and σpa ame e s wi hin ISM, and subsequen ly calcula ed x′HS o gi en empe a u e was used o calcula e o al mola suscep ibili y as =x x x(1 ) HS HS HS (2) = + +x x x x( ) (1 ) mol HS HS HS HS HS HS (3) whe e x HS is he esidual mola ac ion o he HS s a e a a low empe a u e due o incomple e spin c osso e , and x″HS is escaled high-spin ac ion calcula ed om ISM esul ing in he o al high-spin mole ac ion xHS equal o xHS =x″HS +x HS. The mola suscep ibili y o he HS and LS species was calcula ed by he Cu ie law. The i ed pa ame e s a e lis ed in Table S3 and plo ed in Figu e 3 o c ys al samples and in Figu e S4 o mic oc ys alline p ecipi a es. E iden ly, he e is small a ia ion o he coope a i i y Γand en opy pa ame e e wi hin he p epa ed c ys al ba ches o 1, and a ia ions o T1/2↓and T1/2↑a e mainly due o a a ia ion o Δ. Fu he mo e, he e is a signi ican inc ease o he dis ibu ion pa ame e σ o he mic oc ys alline p ecipi a es, Table S3. We also heo e ically a emp ed o in es iga e he impac o di e en sol en s on he molecula geome y and he ene gies o he LS and HS isome o 1using densi y unc ional heo y (DFT) and u ilizing ORCA 5.0 so wa e. 14 We selec ed h ee unc ionals based on published benchma k s udies, 15−17 namely, OPBE, 18 2SCAN, 19 and B3LYP*(B3LYP wi h educed Ha ee−Fock exchange o 15%) 20 and also included he a om-pai wise dispe sion co ec ion (D4). 21 The op i- miza ion was done in a acuum, chlo o o m, and me hanol wi h he C-PCM implici sol a ion model. 22,23 Impac o Figu e 3. Tempe a u e dependence he high-spin mola ac ion xHS acco ding o ISM ( op), he ISM pa ame e s (middle), and ansi ion empe a u es (bo om) o c ys alline samples o 1. C ys al G ow h & Design pubs.acs.o g/c ys al Communica ion h ps://doi.o g/10.1021/acs.cgd.2c01411 C ys . G ow h Des. 2023, 23, 1323−1329 1325 sol en s is demons a ed o he HS s a e o [Fe(3,5-Cl- L5)(NCSe)] in Figu e 4. I seems ha OPBE unde es ima es he Fe−NCSe bond, whe eas B3LYP*and 2SCAN o e - es ima es he bond leng hs o amino-ni ogen o 3,5-Cl-L5. In he case o he LS molecula geome ies, OPBE hea ily unde es ima es all Fe−N bond leng hs (Figu e S5). Mo eo e , he e is also signi ican a ia ion in bond leng hs induced by he implici sol a ion model, which poin s o he impo ance o in e molecula in e ac ions. The analysis o he elec onic ene gy di e ences be ween he HS and LS isome s e ealed posi i e alues o ΔEel =EelHS − EelLS o all h ee DFT unc ionals, and hus hese unc ionals p ope ly ound he LS s a e wi h lowe elec onic ene gy (Eel), Table S4. As he molecula ib a ions ha e a signi ican impac on he SCO p ope ies, a be e desc ip ion is achie ed wi h he ene gy di e ence co ec ed by he ze o- empe a u e ib a ional ene gy om he equency calcula ion, ΔEel+ZPE, which is depic ed in Figu e 5. Appa en ly, ΔEel+ZPE is signi ican ly a ec ed by applying he implici sol a ion model, and bo h B3LYP*and 2SCAN p o ided easonable alues o he HS-LS sepa a ion. Mo eo e , i seems ha a mo e pola sol en like CH3OH ends o inc ease ΔEel+ZPE, and hus i s abilizes he LS s a e. This is in con adic ion o he expe imen al inding (Figu e 3 and Table S3), o which highe Φ(CH3OH) yielded lowe Δand T1/2 alues. We can specula e ha his disc epancy is caused by he implici sol a ion app oach which canno g asp he e ec o all in e molecula in e ac ions p ope ly, o he p ope ies o 1in he solid s a e simply canno be encompassed by such an app oach a all. Howe e , i he p esen ed heo e ical calcula ions a e no decep i e, pe haps i mos likely leads o he conclusion ha he epo ed phenomenon is no go e ned by he mody- namics, bu by he kine ics o he c ys al g ow h o 1unde a ious con en s o chlo o o m and me hanol in c ys allizing solu ions. Hence, he quali y o he c ys alline ma e ial and SCO p ope ies a e a ec ed by a sol en mix u e, bu he sol en molecules do no coc ys allize. One o he possible app oaches o es his hypo hesis is o co ela e pa ame e s such as c ys al mosaici y wi h he obse ed magne ic beha io . The e o e, we decided o p epa e se e al ba ches o 1 c ys allized a di e en c ys alliza ion a es. As was men ioned abo e, he bes c ys als we e ob ained in he ba ch o 1_Φ0.25. Howe e , he ba ches c ys allized om solu ions wi h a majo chlo o o m ac ion (Φ0.25 and Φ0.05) ha e p ac ically he same magne ic p ope ies (Figu e 3). Thus, we decided o c ys allize 1 om Φ0.5 and Φ0.83 solu ions, because 1_Φ0.5 and 1_Φ0.83 di e in T1/2↓(114 K o 1_Φ0.5 and 103 K o 1_Φ0.83), and hei spin ansi ion on Figu e 4. G aphical compa ison o he dono −accep o bond dis ances be ween X- ay da a (do ed lines) and he espec i e DFT me hods (B3LYP*, OPBE, and 2SCAN) o he high-spin s a e o 1. Figu e 5. G aphical compa ison he ene gy di e ence co ec ed by he ze o- empe a u e ib a ional ene gy om he equency calcula ion ΔEel+ZPE be ween he HS and LS s a es o di e en DFT me hods applied o 1. C ys al G ow h & Design pubs.acs.o g/c ys al Communica ion h ps://doi.o g/10.1021/acs.cgd.2c01411 C ys . G ow h Des. 2023, 23, 1323−1329 1326 cooling is s ill accessible using s anda d comme cial c yogenic de ices (abo e 80 K). Fo p epa a ion o he ba ches, we used he same eac ion p ocedu es as a e desc ibed in Suppo ing In o ma ion, bu he mo he liquo s we e c ys allized using h ee di e en c ys alliza ion a es: as (≈1day), slow (up o 4 days), and e y slow (≥7 days). The majo i y o he used single c ys als we e ob ained o all he ba ches c ys allized om Φ0.5 solu ions ega dless o he a e o c ys alliza ion used. Howe e , also e y slow c ys alliza ion om he Φ0.83 solu ions esul ed in he p oduc ion o a ew sui able single c ys als. The c ys al mosaici y was de e mined aking in o consid- e a ion he esul s o p e ious wo k on mosaici y in SCO complexes. 24 We se expe imen al condi ions o be as iden ical as possible o all he in es iga ed specimens. The expe imen was conduc ed a 150 K, which is well abo e he highes T1/2↓ (Table S3). The da a we e collec ed using ω-scans (wid h 0.5 deg), and he exposi ion ime was adjus ed o each c ys al based on i s size, aiming o 0.83 Å esolu ion, comple eness abo e 99%, da a edundancy > 3, and I/σ> 10. As was al eady men ioned, he c ys als o 1a e e y hin ( ypically ≈0.05 mm in wo dimensions), needle-like shaped g owing in clumps o o e lapping specimens, which makes i challenging o in es iga e he s a is ically ele an numbe o c ys alli es wi hin a easonable measu emen ime. Thus, we we e capable o pe o ming measu emen s o a limi ed numbe (14) o single c ys als. I is impo an o no e ha he as majo i y o he p epa ed c ys als we e no sui able o single-c ys al expe imen s, and hus he esul s ob ained only ep esen hose c ys als ha me he necessa y c i e ia. A e collec ing each se o da a a 150 K, we de e mined T1/2↓ o each c ys al by measu ing uni cell pa ame e s s a ing om 125 K down o 80 K in dec emen s o 5 K. The occu ence o he SCO phenomenon was eco ded be ween wo measu ed empe a u e poin s, and he a e age o hese alues was used o isualiza ion pu poses. The T1/2↓ alue o c ys als ha emained in he high spin phase a 80 K was se o 70 K o isualiza ion pu poses. The dis ibu ion o he de e mined T1/2↓ alues is shown (Figu e 6A). The esul s suppo ed ou hypo hesis ha he speed o c ys alliza ion a ec s he quali y o c ys als and he T1/2↓ alue. C ys als c ys allized in he ” as ” and “slow” modes showed T1/2↓ alues abo e 100 K. C ys als ha c ys allized “ e y slowly” showed Figu e 6. Plo o T1/2↓ e sus c ys alliza ion a e (A). The colo ed boxes a e used o highligh he c ys alliza ion a e, wi h a ligh e colo indica ing slowe c ys alliza ion. The plo s o Rin s T1/2↓(B), e3 s T1/2↓(C), and ea g s T1/2↓(D). The alue o ea g was calcula ed as he a i hme ic a e age o componen s e1,e2, and e3. In all plo s, he T1/2↓ alue o c ys als ha emained in he high spin phase down o 80 K was assigned as 70 K o isualiza ion pu poses. C ys al G ow h & Design pubs.acs.o g/c ys al Communica ion h ps://doi.o g/10.1021/acs.cgd.2c01411 C ys . G ow h Des. 2023, 23, 1323−1329 1327 T1/2↓ alues below 90 K wi h mos o hem ha ing T1/2↓e en below 80 K. The esul s o he X- ay di ac ion measu emen s we e e alua ed in he C ysAlisP o so wa e. 25 As a i s indica ion o he c ys al quali y, we inspec ed he equi alency o symme y equi alen e lec ions (Rin ) in he s udied c ys als. The e is no s ong co ela ion be ween T1/2↓and Rin , bu appa en ly, he c ys als wi h lowe T1/2↓ alues end o ha e la ge Rin and ice e sa (Figu e 6B). The C ysAlisP o so wa e p o ides he mosaici y in h ee di ec ions (e1,e2, and e3) by i ing a Gaussian unc ion o he peak. 26,27 Al hough hese pa ame e s do no measu e he mosaici y di ec ly, a ia ions in he alues o e1,e2, and e3can indica e changes in he mosaici y o he s udied c ys als and hus hei quali y. 28 Some au ho s only use he e3pa ame e due o i s co ela ion wi h mosaici y alues ob ained om o he da a in eg a ion me hods. 26 The esul s e ealed ha he e2componen a ied sligh ly among he measu emen s (0.76− 0.96°), while la ge a ia ions we e obse ed o e1(0.75− 2.61°) and e3(0.71−1.66°). As pe p e ious epo s, o e alua ion o mosaici y, we conside ed he alues o e3and he a i hme ic a e age (ea g) 29 o all h ee componen s e1,e2, and e3 (Figu e 6C−D, Table S5). As wi h Rin , he esul s o ea g and e3did no show a s ong linea co ela ion; howe e , c ys als wi h highe T1/2↓ alues end o ha e lowe alues o eand e3 and ice e sa. In summa y, o he bes o ou knowledge, such an unp eceden ed sol en -induced a ia ion o SCO spin- ansi ion empe a u e as was discussed o 1has no been epo ed ye . We showed ha he di e en c ys alliza ion a es p oduced c ys als exhibi ing di e en SCO c i ical empe - a u es. Ve y slow c ys alliza ion (≥7 days) o he Φ0.5 and Φ0.83 solu ions esul ed in o c ys als exhibi ing low SCO c i ical empe a u es (T1/2↓< 90 K), while as e c ys alliza ion (sho e han 4 days) led o la ge T1/2↓ alues (>100 K). The pe o med di ac ion expe imen s indica e ha c ys als wi h low T1/2↓ alues end o ha e la ge mosaici y pa ame e s and Rin , and hus hey a e o lowe quali y han hose wi h la ge T1/2↓ alues. ■ASSOCIATED CONTENT * sı Suppo ing In o ma ion The Suppo ing In o ma ion is a ailable ee o cha ge a h ps://pubs.acs.o g/doi/10.1021/acs.cgd.2c01411. Syn hesis, c ys allog aphic da a, magne ic measu emen s, DFT calcula ion de ails, and powde di ac ion pa e ns (PDF) Accession Codes CCDC 1909057 and 2223462−2223463 con ain he supple- men a y c ys allog aphic da a o his pape . These da a can be ob ained ee o cha ge ia www.ccdc.cam.ac.uk/da a_ eques / ci , o by emailing [email p o ec ed], o by con ac ing The Camb idge C ys allog aphic Da a Cen e, 12 Union Road, Camb idge CB2 1EZ, UK; ax: +44 1223 336033. ■AUTHOR INFORMATION Co esponding Au ho s I an Nemec −Cen al Eu opean Ins i u e o Technology, B no Uni e si y o Technology, 61200 B no, Czech Republic; Depa men o Ino ganic Chemis y, PalackyUni e si y, 77900 Olomouc, Czech Republic; o cid.o g/0000-0003- 3231-7849; Email: [email p o ec ed] Rado an He chel −Depa men o Ino ganic Chemis y, PalackyUni e si y, 77900 Olomouc, Czech Republic; o cid.o g/0000-0001-8262-4666; Email: [email p o ec ed] Au ho Lucie Ko ásko á −Cen al Eu opean Ins i u e o Technology, B no Uni e si y o Technology, 61200 B no, Czech Republic; o cid.o g/0000-0003-4825-3616 Comple e con ac in o ma ion is a ailable a : h ps://pubs.acs.o g/10.1021/acs.cgd.2c01411 Au ho Con ibu ions The manusc ip was w i en h ough con ibu ions o all au ho s. All au ho s ha e gi en app o al o he inal e sion o he manusc ip . No es The au ho s decla e no compe ing inancial in e es . ■ACKNOWLEDGMENTS The au ho s (I.N. and R.H.) acknowledge inancial suppo om ins i u ional sou ces o he Depa men o Ino ganic Chemis y and PalackyUni e si y Olomouc, Czech Republic. We also acknowledge he CzechNanoLab Resea ch In a- s uc u e suppo ed by MEYS CR (LM2018110) o he measu emen o some o he magne ic da a. I.N. is g a e ul o Jakub Wojciechowski o discussions abou mosaici y e alua- ion in C ysAlisP o so wa e. ■REFERENCES (1) Ba i, R. A.; Si a die e, J. Low-Spin-High-Spin T ansi ions in T ansi ion-Me al-Ion Compounds. Phys. Re . B 1972,5(11), 4466− 4471. (2) Wajn lasz, J. E ude de La T ansi ion “Low Spin”-“High Spin” Dans Les Complexes Oc aed iques d’ion de T ansi ion. Phys. s a us solidi 1970,40 (2), 537−545. (3) Boca, R.; Line , W. Is The e a Need o New Models o he Spin C osso e ? 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(29) Fa ley, C.; Bu ks, G.; Siege , T.; Jue s, D. H. Imp o ed Rep oducibili y o Uni -Cell Pa ame e s in Mac omolecula C y- oc ys allog aphy by Limi ing Dehyd a ion du ing C ys al Moun ing. Ac a C ys allog . Sec . D Biol. C ys allog . 2014,70 (8), 2111−2124. C ys al G ow h & Design pubs.acs.o g/c ys al Communica ion h ps://doi.o g/10.1021/acs.cgd.2c01411 C ys . G ow h Des. 2023, 23, 1323−1329 1329 Recommended by ACS Spin-C osso e Beha io s o I on(II) Complexes Bea ing Halogen Ligands in Solid S a e and Solu ion Ju Wang, Jun Tao, e al. JANUARY 12, 2023 INORGANIC CHEMISTRY READ High-Tempe a u e Spin C osso e in FeIII N4O2 Complexes Inco po a ing an [R-sal2323] Backbone Kyle J. Howa d-Smi h, Feng Li, e al. JANUARY 11, 2023 CRYSTAL GROWTH & DESIGN READ Elas ic P ope ies o he I on(II)–T iazole Spin C osso e Complexes [Fe(H z)2 z]BF4 and [Fe(NH2 z)3]SO4 Damian Paliwoda, Azzedine Bousseksou, e al. 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