Synthesis and structural characterization of a diruthenium pentalene complex, \([\hbox {Cp}^{*}\hbox {Ru}\{(\hbox {Cp}^{*}\hbox {Ru})_{2}\hbox {B}_{6}\hbox {H}_{14}\}(\hbox {Cp}^{*}\hbox {Ru})]\)

  • Benson Joseph
  • Subrat Kumar Barik
  • Soumya Kumar Sinha
  • Thierry Roisnel
  • Sundargopal Ghosh
Regular Article



Treatment of nido-[1,2-(Cp*Ru)\(_{2}\)(\(\mu \)-H)\(_{2}\)B\(_{3}\)H\(_{7}\)], 1 with five equivalents of Te powder led to the isolation of diruthenium pentalene analogue \([(\hbox {Cp*}\hbox {Ru})\{(\hbox {Cp*}\hbox {Ru})_{2}\hbox {B}_{6}\hbox {H}_{14}\}(\hbox {RuCp*})]\), 2 and a metal indenyl complex \([(\hbox {Cp*}\hbox {Ru})_{2}\hbox {B}_{2}\hbox {H}_{6}\hbox {C}_{6}\hbox {H}_{3}(\hbox {CH}_{3})\)], 3. The \([(\hbox {Cp*}\hbox {Ru})_{2}\hbox {B}_{6}\hbox {H}_{14}\)] fragment in 2 may be considered as a true metal–boron analogue of \(\upeta ^{5}\)-\(\upeta ^{5}\)-pentalene ligand (\(\hbox {C}_{8}\hbox {H}_{6})\) and \([(\hbox {Cp*}\hbox {Ru})\hbox {B}_{2}\hbox {H}_{6}\hbox {C}_{6}\hbox {H}_{3}(\hbox {CH}_{3})\)] fragment in 3 is an analogue of \(\upeta ^{5}\)-indenyl ligand. The solid-state X-ray structures were unambiguously determined by crystallographic analysis of compounds 2 and 3. Further, the density functional theory (DFT) calculations were performed to investigate the bonding and the electronic properties of 2a (Cp analogue of 2). The frontier molecular orbital analysis of both 2a and 2b (Cp analogue of \([(\hbox {Cp*}\hbox {Ru})\hbox {B}_{8}\hbox {H}_{14}(\hbox {RuCp*})])\) reveals a lower HOMO–LUMO gap indicating less thermodynamic stability.

Graphical Abstract

SYNOPSIS Treatment of nido-[1,2-(Cp\({*}\)Ru)\(_{2}(\upmu \)-H)\(_{2}\)B\(_{3}\)H\(_{7}\)] with Te powder led to the isolation of diruthenium pentalene analogue \([(\hbox {Cp*}\hbox {Ru})\{(\hbox {Cp*}\hbox {Ru})_{2}\hbox {B}_{6}\hbox {H}_{14}\}(\hbox {RuCp*})]\) and a metal indenyl complex \([(\hbox {Cp*}\hbox {Ru})_{2}\hbox {B}_{2}\hbox {H}_{6}\hbox {C}_{6}\hbox {H}_{3}(\hbox {CH}_{3})\)].


Ruthenium boron pentalene indenyl metallaborane 



The generous support of the Council of Scientific & Industrial Research, CSIR (Project No. 01(2837)/15/EMR-II), New Delhi, India, is gratefully acknowledged. B.J. and S.K.B. thank UGC and IIT Madras for research fellowships. We are very thankful to Dr. Bijan Mondal for scientific discussion. We thank Dr. Babu Varghese (SAIF, IIT Madras) for X-ray data analysis. IIT Madras is gratefully acknowledged for computational facilities.

Supplementary material

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  1. 1.
    Weiss R and Grimes R N 1977 New ferraboranes. structural analogs of hexaborane(10) and ferrocene. A complex of cyclic \(\text{ B }_{5}\text{ H }_{10}^{-}\), a counter part of \(\text{ C }_{5}\text{ H }_{5}^{-}\) J. Am. Chem. Soc.  99 8087CrossRefGoogle Scholar
  2. 2.
    Venable T L, Sinn E and Grimes R N 1984 1-[(\(\upeta ^{5}\text{- }\text{ C }_{5}\text{ R }_{5})\text{ Co }]\text{ B }_{4}\text{ H }_{8}\)(R = H or Me) sandwich complexes containing a square cyclic \(\text{ B }_{4}\text{ H }_{8}^{2-}\) ligand analogous to \(\text{ C }_{4}\text{ H }_{4}^{2-}\): Structural and spectroscopic studies J. Chem. Soc. Dalton Trans. 2275Google Scholar
  3. 3.
    Ghosh S, Noll B C and Fehlner T P 2005 Borane mimics of classic organometallic compounds: [(Cp*Ru)\(\text{ B }_{8}\text{ H }_{14}\)(RuCp*)]\(^{0+}\), Isoelectronic analogues of dinuclear pentalene complexes Angew. Chem. Int. Ed. 44 6568CrossRefGoogle Scholar
  4. 4.
    Ghosh S, Noll B C and Fehlner T P 2008 Expansion of iridaborane clusters by addition of monoborane. Novel metallaboranes and mechanistic detail Dalton Trans. 371Google Scholar
  5. 5.
    (a) De A, Zhang Q-F, Mondal B, Cheung L F, Kar S, Saha K, Varghese B, Wang L-S and Ghosh S 2018 [(\(\text{ Cp }_{2}\text{ M })_{2}\text{ B }_{9}\text{ H }_{11}\)] (M = Zr or Hf) early transition metal ‘guarded’ heptaborane with strong covalent and electrostatic bonding Chem. Sci9 1976; (b) Ghosh S, Rheingold A L and Fehlner T P 2001 Metallaboranes of the earlier transition metals. An arachno nine-vertex, nine-skeletal electron pair rhenaborane of novel shape: importance of total vertex connectivities in such systems Chem. Commun. 895Google Scholar
  6. 6.
    (a) Roy D K, Bose S K, Geetharani K, Chakrahari K K V, Mobin S M and Ghosh S 2012 Synthesis and structural characterization of new divanada- and diniobaboranes containing chalcogen atoms Chem. Eur. J.  18 9983; (b) Dhayal R S, Chakrahari K K V, Varghese B, Mobin S M and Ghosh S 2010 Chemistry of Molybdaboranes: Synthesis, structures, and characterization of a new class of open-cage dimolybdaheteroborane clusters Inorg. Chem.  49 7741; (c) Bose S K, Geetharani K, Ramkumar V, Varghese B and Ghosh S 2010 Chemistry of Vanadaboranes: Synthesis, structures, and characterization of organovanadium sulfide clusters with disulfido linkage Inorg. Chem.  49 2881; (d) Bose S K, Geetharani K, Varghese B and Ghosh S 2010 Unusual organic chemistry of a metallaborane substrate: Formation of tantalaborane complex with bridging acyl group (\(\mu \)-\(\upeta ^{2})\) Inorg. Chem.  49 6375; (e) Bose S K, Geetharani K and Ghosh S 2011 C–H Activation of arenes and heteroarenes by early transition metallaborane Chem. Commun. 47 11996; (f) Bose S K, Geetharani K, Varghese B and Ghosh S 2011 Condensed Tantalaborane clusters: Synthesis and structures of [(Cp*Ta)\(_{2}\text{ B }_{5}\text{ H }_{7}\{\text{ Fe }(\text{ CO })_{3}\}_{2}\)] and [(Cp*Ta)\(_{2}\text{ B }_{5}\text{ H }_{9}\{\text{ Fe }(\text{ CO })_{3}\}_{4}\)Inorg. Chem. 50 2445; (g) Geetharani K, Krishnamoorthy B S, Kahlal S, Mobin S M, Halet J-F and Ghosh S 2012 Synthesis and characterization of hypoelectronic Tantalaboranes. Comparison of the geometric and electronic structures of [(Cp*TaX)\(_{2}\text{ B }_{5}\text{ H }_{11}\)] (X = Cl, Br and I) Inorg. Chem51 10176; (h) Bose K, Geetharani K, Sahoo S, Reddy K H K, Varghese B, Jemmis E D and Ghosh S 2011 Synthesis, characterization, and electronic structure of new type of heterometallic boride clusters Inorg. Chem. 50 9414Google Scholar
  7. 7.
    (a) Sahoo S, Mobin S M and Ghosh S 2010 Direct insertion of Sulfur, Selenium and Tellurium atoms into metallaborane cages using chalcogen powders J. Organomet. Chem. 695 945; (b) Thakur A, Sao S, Ramkumar V and Ghosh S 2012 Novel class of heterometallic cubane and boride clusters containing heavier group 16 elements Inorg. Chem. 51 8322; (c) Geetharani K, Bose S K, Sahoo S and Ghosh S 2011 A family of heterometallic cubane-type clusters with an exo-Fe(CO)\(_{3}\) fragment anchored to the cubane Angew. Chem. Int. Ed. 50 3908; (d) Geetharani K, Bose S K, Pramanik G, Saha T K, Ramkumar V and Ghosh S 2009 An efficient route to group 6 and 8 metallaborane compounds: Synthesis of arachno-[Cp*Fe(CO)\(\text{ B }_{3}\text{ H }_{8}\)] and closo-[(Cp*M)\(_{2}\text{ B }_{5}\text{ H }_{9}\)] (M = Mo, W) Eur. J. Inorg. Chem. 1483; (e) Roy D K, Mondal B, Shankhari P, Anju R S, Geetharani K, Mobin S M and Ghosh S 2013 Vertex-fused metallaborane clusters: Synthesis, characterization and electronic structure of [(\(\upeta ^{5}\text{- }\text{ C }_{5}\text{ Me }_{5}\text{ Mo })_{3}\text{ MoB }_{9}\text{ H }_{18}\)] Inorg. Chem.  5 6705 (f) Dhayal R S, Sahoo S, Reddy K H K, Mobin S M, Jemmis E D and Ghosh S 2010 Vertex-fused metallaborane clusters: synthesis, characterization and electronic structure of [(\(\upeta ^{5}\text{- }\text{ C }_{5}\text{ Me }_{5}\text{ Mo })_{3}\text{ MoB }_{9}\text{ H }_{18}\)] Inorg. Chem. 49 900; (g) Sahoo S, Reddy K H K, Dhayal R S, Mobin S M, Ramkumar V, Jemmis E D and Ghosh S 2009 Chlorinated hypoelectronic dimetallaborane clusters: synthesis, characterization, and electronic structures of (\(\upeta ^{5}\text{- }\text{ C }_{5}\text{ Me }_{5}\text{ W })_{2}\text{ B }_{5}\text{ H }_{n}\text{ Cl }_{m}\) (\(n = 7\), \(m = 2\) and \(n = 8\), \(m = 1\)Inorg. Chem.  48 6509Google Scholar
  8. 8.
    Geetharani K, Bose S K, Sahoo S, Varghese B, Mobin S M and Ghosh S 2011 Cluster expansion reactions of group 6 and 8 metallaboranes using transition metal carbonyl compounds of groups 7-9 Inorg. Chem.  50 5824CrossRefGoogle Scholar
  9. 9.
    (a) Roy D K, Mondal B, Anju R S and Ghosh S 2015 Chemistry of Diruthenium and dirhodium analogues of pentaborane(9): Synthesis and characterization of metal N,S-heterocyclic carbene and B-agostic complexes Chem. Eur. J21 3640; (b) Ramalakshmi R, Saha K, Roy D K, Varghese B, Phukan A K and Ghosh S 2015 New routes to a series of \(\upsigma \)-borane/borate complexes of Molybdenum and Ruthenium Chem. Eur. J21 17191; (c) Roy D K, De A, Panda S, Varghese B and Ghosh S 2015 Chemistry of N,S-heterocyclic carbene and metallaboratrane complexes: A new \(\upeta ^{3}\)-BCC-borataallyl complex Chem. Eur. J21 13732; (d) Anju R S, Roy D K, Mondal B, Yuvaraj K, Arivazhagan C, Saha K, Varghese B and Ghosh S 2014 Reactivity of diruthenium and dirhodium analogues of pentaborane(9): Agostic versus boratrane complexes Angew. Chem. Int. Ed. 53 2873; (e) Anju R S, Roy D K, Geetharani K, Mondal B, Varghese B and Ghosh S 2013 A fine tuning of metallaborane to bridged-boryl complex, \([(\text{ Cp }^{*}\text{ Ru })_{2}(\mu \text{- }\text{ H })(\mu \text{- }\text{ CO })(\mu \text{- }\text{ Bcat })]\) (cat = 1,2-\(\text{ O }_{2}\text{ C }_{6}\text{ H }_{4}\); \(\text{ Cp }^{*} = \upeta ^{5}\text{- }\text{ C }_{5}\text{ Me }_{5})\) Dalton Trans. 42 12828; (f) Bose S K, Roy D K, Shankhari P, Yuvaraj K, Mondal B, Sikder A and Ghosh S 2013 Syntheses and characterization of new vinyl-borylene complexes by the hydroboration of alkynes with \([(\mu_{3}\text{- }\text{ BH })(\text{ Cp }^{*}\text{ RuCO })_{2}(\mu \text{- }\text{ CO })\text{ Fe }(\text{ CO })_{3}\)Chem. Eur. J. 19 2337; (g) Yuvaraj K, Roy D K, Geetharani K, Mondal B, Anju V P, Shankhari P, Ramkumar V and Ghosh S 2013 Chemistry of homo- and heterometallic bridged-borylene complexes Organometallics 3 2705; (h) Anju R S, Saha K, Mondal B, Dorcet V, Roisnel T, Halet J-F and Ghosh S 2014 Chemistry of diruthenium analogue of pentaborane(9) with heterocumulenes: towards novel trimetallic cubane-type clusters Inorg. Chem53 10527Google Scholar
  10. 10.
    (a) Roy D K, Bose S K, Anju R S, Ramkumar V and Ghosh S 2012 Synthesis and structure of dirhodium analogue of octaborane-12 and decaborane-14 Inorg. Chem. 51 10715; (b) Roy D K, Mondal B, Shankhari P, Anju R S, Geetharani K, Mobin S M and Ghosh S 2013 Supraicosahedral polyhedra in metallaboranes: Synthesis and structural characterization of 12-, 15-, and 16-vertex rhodaboranes Inorg. Chem.  52 6705; (c) Roy D K, Bose S K, Anju R S, Mondal B, Ramkumar V and Ghosh S 2013 Boron beyond the icosahedral barrier: A 16-vertex metallaborane Angew. Chem. Int. Ed.  52 3222; (d) Sharmila D, Yuvaraj K, Barik S K, Roy D K, Chakrahari K K V, Ramalakshmi R, Mondal B, Varghese B and Ghosh S 2013 New heteronuclear bridged borylene complexes that were derived from [Cp*CoCl\(\_{2}\)] and mono-metal carbonyl fragments Chem. Eur. J19 15219Google Scholar
  11. 11.
    Koelle U and Kossakowski J 1992 Di-\(\mu \)-chloro-bis[(\(\upeta ^{5}\)-pentamethylcyclopentadienyl)chloro ruthenium(III), \([\text{ Cp }^{*}\text{ RuCl }_{2}]_{2}\) and Di-\(\mu \)-methoxo-bis [(\(\upeta ^{5}\)-pentamethylcyclopentadienyl)-diruthenium(II)], \([\text{ Cp }^{*}\text{ RuOMe }]_{2}\) Inorg. Synth29 225Google Scholar
  12. 12.
    Lei X, Shang M and Fehlner T P 1999 Chemistry of dimetallaboranes derived from the reaction of \([\text{ Cp }^{*}\text{ MCl }_{2}]_{2}\) with Monoboranes (M = Ru, Rh; Cp* = \(\upeta ^{5}\text{- }\text{ C }_{5}\text{ Me }_{5})\) J. Am. Chem. Soc.  121 1275CrossRefGoogle Scholar
  13. 13.
    Ryschkewitsch G E and Nainan K C 1974 Inorg. Synth. 15 111Google Scholar
  14. 14.
    Although our aim was to isolate Te incorporated metallahetroborane clusters, we were able to isolate compounds 2 and 3 in poor yields. Note that the \(^{11}\text{ B }\) NMR of the reaction mixture indicated several boron containing products, however we were unable to isolate any of these due to their instability. Compound 3 was isolated in a very poor yield and all our attempts to reproduce this molecule were failed. Thus, compound 3 was characterized by limited spectroscopic data and an X-ray structural analysis.Google Scholar
  15. 15.
    (a) Sheldrick G M 1997 SHELXS-97 University of Gottingen: Germany; (b) SIR92, Altornare A, Cascarano G, Giacovazzo C and Guagliardi A 1993 Completion and refinement of crystal structures with SIR92 J. Appl. Cryst. 26 343; (c) Sheldrick G M 1997 SHELXL-97 University of Gottingen: GermanyGoogle Scholar
  16. 16.
    Frisch M J, Trucks G W, Schlegel H B, Scuseria G E, Robb M A, Cheeseman J R, Scalmani G, Barone V, Mennucci B, Petersson G A, Nakatsuji H, Caricato M, Li X, Hratchian H P, Izmaylov A F, Bloino J, Zheng G, Sonnenberg J L, Hada M, Ehara M, Toyota K, Fukuda R, Hasegawa J, Ishida M, Nakajima T, Honda Y, Kitao O, Nakai H, Vreven T, Montgomery J A. Jr, Peralta J E, Ogliaro F, Bearpark M, Heyd J J, Brothers E, Kudin K N, Staroverov V N, Keith T, Kobayashi R, Normand J, Raghavachari K, Rendell A, Burant J C, Iyengar S S, Tomasi J, Cossi M, Rega N, Millam J M, Klene M, Knox J E, Cross J B, Bakken V, Adamo C, Jaramillo J, Gomperts R, Stratmann R E, Yazyev O, Austin A J, Cammi R, Pomelli C, Ochterski J W, Martin R L, Morokuma K, Zakrzewski V G, Voth G A, Salvador P, Dannenberg J J, Dapprich S, Daniels A D, Farkas O, Foresman J B, Ortiz J V, Cioslowski J and Fox D J 2010 Gaussian 09, Revision C.01; Gaussian, Inc.: Wallingford, CTGoogle Scholar
  17. 17.
    Perdew J P, Burke K and Ernzerhof M 1996 Generalized gradient approximation made simple Phys. Rev. Lett. 77 3865CrossRefGoogle Scholar
  18. 18.
    (a) London F 1937 Théorie quantique des courants interatomiques dans les combinaisons aromatiques J. Phys. Radium. 8 397; (b) Ditchfield R 1974 Self-consistent perturbation theory of diamagnetism Mol. Phys. 27 789; (c) Wolinski K, Hinton J F and Pulay P 1990 Efficient implementation of the gauge-independent atomic orbital method for nmr chemical shift calculations J. Am. Chem. Soc. 112 8251Google Scholar
  19. 19.
    (a) Schreckenbach G and Ziegler T 1995 calculation of NMR shielding tensors using gauge-including atomic orbitals and modern density functional theory J. Phys. Chem. 99 606; (b) Schreckenbach G and Ziegler T 1997 Calculation of NMR shielding tensors based on density functional theory and a scalar relativistic Pauli-type Hamiltonian. The application to transition metal complexes Int. J. Quantum Chem. 61 899; (c) Schreckenbach G and Ziegler T 1996 The calculation of NMR shielding tensors based on density functional theory and the frozen-core approximation Int. J. Quantum Chem. 60 753; (d) Wolff S K and Ziegler T 1998 Calculation of DFT-GIAO NMR shifts with the inclusion of spin-orbit coupling J. Chem. Phys. 109 895; (e) Wolff S K, Ziegler T, van Lenthe E and Baerends E J 1999 Density functional calculations of nuclear magnetic shieldings using the zeroth-order regular approximation (ZORA) for relativistic effects: ZORA nuclear magnetic resonance J. Chem. Phys. 110 7689Google Scholar
  20. 20.
  21. 21.
    Lu T and Chen F 2012 Multiwfn: a multifunctional wavefunction analyzer J. Comput. Chem. 33 580CrossRefGoogle Scholar
  22. 22.
    (a) Bunel E E, Valle L, Jones N L, Carrol P J, Barra C, González M, Munoz N, Visconti G, Aizman A and Manríquez J M 1988 Bis[(pentamethylcyclopentadienyl)metal]pentalenes. A new class of highly delocalized, fused metallocenes J. Am. Chem. Soc110 6596; (b) Manríquez JM, Ward M D, Reiff W M, Calabrese J C, Jones N L, Carroll P J, Bunel E E and Miller J S 1995 Structural and physical properties of delocalized mixed-valent \([\text{ Cp }^{*}\text{ M }\text{(pentalene) }\text{ M }^{\prime }\text{ Cp }^{*}]^{{\rm n}+}\) and \([\text{ Cp }^{*}\text{ M }\text{(indacene) }\text{ M }^{\prime }\text{ Cp }^{*}]^{{\rm n}+}\) \((\text{ M }, \text{ M }^{\prime } = \text{ Fe }\), Co, Ni; n = 0, 1, 2) Complexes J. Am. Chem. Soc. 117 6182Google Scholar
  23. 23.
    (a) Tait C D, Garner J M, Collman J P, Sattelberger A P and Woodruff W H 1989 Vibrational study of multiply metal-metal bonded ruthenium porphyrin dimers J. Am. Chem. Soc. 111 7806; (b) Poizat O and Sourisseau C 1984 Infrared, Raman, and resonance Raman studies of the \(\text{ ru }(2,2^{\prime }\text{- }\text{ bpy })_{3}^{2+}\) cation in its chloride crystal and as an intercalate in the layered \(\text{ MnPS }_{3}\) Compound J. Phys. Chem. 88 3007Google Scholar
  24. 24.
    Barik S K, Chowdhury M G, De S, Parameswaran P and Ghosh S 2016 Extended sandwich molecules displaying direct metal–metal bonds Eur. J. Inorg. Chem. 4546Google Scholar
  25. 25.
    (a) Boucher B, Ghosh S, Halet J-F, Kahlal S and Saillard J-Y 2012 Bonding and electronic structure of \(\text{ Cp }^{*}_{2}\text{ Ru }_{2}(\text{ B }_{8}\text{ H }_{14})\), A metallaborane analogue of dinuclear pentalene complexes J. Organomet. Chem. 721-722 167; (b) Garland M T, Saillard J-Y, Chávez I, Oëlckers B and Manríquez J M 1997 Molecular orbital calculations of binuclear systems of Fe, Co and Ni derivatives of pentalene, s-indacene and as-indacene J. Mol. Struct. 390 199Google Scholar
  26. 26.
    Kudinov A R, Petrovskii P V, Struchkov T, Yanovskii A I and Rybinskaya M I 1991 Synthesis of slipped triple- and tetra-decker cationic ruthenium complexes with the \(\mu \), \(\upeta ^{5}\);\(\upeta ^{6}\)-indenyl ligand. X-Ray structure of [(\(\upeta ^{5}\text{- }\text{ C }_{5}\text{ H }_{5})\text{ Ru }(\mu \),\(\upeta ^{5}\):\(\upeta ^{6}\text{- }\text{ C }_{9}\text{ H }_{7}\text{- }\text{ Ru }(\upeta \text{- }\text{ C }_{5}\text{ Me }_{5})]\text{ PF }_{6}\) J. Organomet. Chem. 421 91CrossRefGoogle Scholar
  27. 27.
    (a) Mercier A, Yeo W C, Chou J, Chaudhuri P D, Bernardinelli G and Kündig E P 2009 Synthesis of highly enantiomerically enriched planar chiral ruthenium complexes via Pd-catalysed asymmetric hydrogenolysis Chem. Commun. 5227; (b) Wagschal S, Mercier A and Kundig E P 2013 Enantioselective desymmetrization of 1,2,3-trisubstituted metallocenes by molybdenum-catalyzed asymmetric intraannular ring-closing metathesis Organometallics 32 7133Google Scholar
  28. 28.
    Ghosh S, Beatty A M and Fehlner T P 2003 Transition-metal variation as a probe of the origins of hypoelectronic metallaboranes: eight- and ten-vertex open ruthenaboranes Angew. Chem. Int. Ed. 42 4678Google Scholar
  29. 29.
    Hoffmann R 1982 Building bridges between inorganic and organic chemistry (nobel lecture) Angew. Chem. Int. Ed. Engl. 21 711CrossRefGoogle Scholar

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© Indian Academy of Sciences 2018

Authors and Affiliations

  1. 1.Department of ChemistryIndian Institute of Technology MadrasChennaiIndia
  2. 2.Institut des Sciences Chimiques de RennesUMR 6226 CNRS-Ecole Nationale Supérieure de Chimie de Rennes-Université de Rennes 1Rennes CedexFrance

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