Mindanao University of Science and Technology C.M. Recto Ave., Lapasan Cagayan de Oro City, City, Philippines Inorganic Cheistry !epartent of Cheistry College of Arts and Sciences
Preparation and Analysis of a Coordination Copo"nd# Synthesis of $Co%&'()*Cl+Cl -perient &o. /0
S"1itted 1y# 2ro"p / 3asa, Marla C. 3aytion, Ana Margarita L. Toas, Toas, I44a May L.
!ate perfored# Septe1er 5, 0/* S"1itted to# Sir 2lenn !. Ongayo
I&TRO!UCTIO& Coordination copo"nds are copo"nds that contain a etal ato or ion 1onded to a fro"p of olec"les ionic copo"nds consisting of a cople ion %a etal ion 6ith its attached olec"les or ions) and a co"nter ion or ions to 1alance the charge. The olec"les or ions attached to the central etal ato are called ligands. A ligand is an ion or olec"le that 1inds to a central etal ato to for a coordination cople. The electron pairs "sed to for the 1onds are donated 1y the ligands, 6hich a7es the ligands Le6is 1ases and the etal ion a Le6is acid. Co1alt%III) fors soe of the ost sta1le and easily8prepared coordination copo"nds. The ligand echange for Co%II) is rapid. The (9 state is inert 6ith 6ith respect to ligand s"1stit"tion. Therefore, coplees of Co%III) are easy to handle and can 1e dissolved in 6ater 6itho"t a rapid change in coposition. A sol"tion of Co%II) is prepared 6ith 6ith a high concentration of the ions or olec"les olec"les that 6e 6ish to introd"ce introd"ce as ligands. The Co%II) Co%II) is then oidi4ed 6ith hydrogen hydrogen peroide, to convert the Co%II) to Co%III). This "s"ally res"lts in a copo"nd 6ith five of the si ligands . In thi this epe eperrien ientt 6e 6il 6ill prep prepar aree chlo chlorropen openta taa ain inec eco1 o1al alt% t%II III) I) chl chlori oride, de, $Co%&'()*Cl+Cl. The Co%III) in this copo"nd has a coordination n"1er of si# five &' ( olec"les olec"les and one Cl: ion, in an octahedral geoetry aro"nd that Co%III) central etal, to give an ion 6ith 6ith a 9 charge. charge. The copo"n copo"nd d has t6o Cl: anions anions to 1alance 1alance that that charge charge..
The
•
copo"nd is prepared 1y dissolving CoCl ;'O in 6ater and adding concentrated aonia sol"tion. Co%'O);9 9 ; &'(
→
Co%&'() *O'9 9 &'59 9 *'O
%/)
The Co%II) is then oidi4ed 6ith hydrogen peroide. Co%&'() *O'9 9 /< 'O
→
Co%&'() * O'9 9 O':
%)
The sol"tion is acidified and heated to coplete the conversion to the desired prod"ct. Co%&'() * O'9 9 '9
→
Co% &'() * O'(9 9 Cl:
→
Co%&'() * Cl9 9 Cl:
→
Co% &'() * O'(9
%()
Co%&'() * Cl9 9 'O
%5)
$Co%&'() *Cl+Cl %s %solid)
%*)
O3=-CTI>-S The o1?ectives of this eperient 6as to prepare a coordination copo"nd$Co%&'( ) * C l+ C l 1y dissolving dissolving CoCl @;'0 in 6ater and adding concentrated aonia sol"tion: aonia it"re, and isolated and synthesi4ed a ; coordinate Co1alt %III) copo"nd. MAT-RIALS The aterials "sed in this eperient 6ere# *0:L 1ea7ers, /0:L and *:L grad"ated cylinder, filter paper, f"nnel, theroeter, iron stand, stirring rod, hot plate, 500:L 1ea7er, 6ash 1ottle, /*:L -rleneyer flas7 and ice. C'-MICALS The cheicals "sed 6ere# CoCl ;'O, &'5Cl %solid), concentrated aonia, 0B 'O, concentrated 'Cl and ethanol. PROC-!URA. Synthes Synthesis is of $Co%&'( $Co%&'()*C )*Cl+ l+Cl Cl e 6eighed approiately 5.0 g of po6dered co1alt chloride ;:hydrate in a /*L -rleneyer -rleneyer flas7. hile hile in the hood, 6e dissolved dissolved .0 g of aoni" chloride chloride in / L of concentrated aonia in a separate 1ea7er and added the it"re to the flas7 of CoCl and s6irled s6irled to dissolve. dissolve. Soe 1ro6n and
vac"" to dra6 the sol"tion a6ay a6a y fro the precipitate. e "se /0 L of ice:cold de:ioni4ed 6ater to transfer any solid reaining in the flas7 into the f"nnel. &ote# The 6ashing techniG"e to "se is /) add ?"st eno"gh ice:cold 6ater to the f"nnel to cover the precipitate, ) allo6 to set a fe6 seconds to 6et all of the solid thoro"ghly, and then () dra6 the 6ash sol"tion thro"gh into the filter flas7. a ashing shing once 6ith ice:cold 6ater is s"fficient. s"fficient. e t"rned off the vac"", and added adde d 0 L of ice cold ethanol to the prod"ct on the filter paper and let this set for a fe6 seconds, and applied the vac"" vac"" again. hen the ethanol has 1een dra6n thro"gh the solid prod"ct, 6e t"rned the vac"" off, and rinsed again 6ith a 0 L portion of ethanol. After After this second rinsing 6ith ethanol, 6e left the vac"" on, and dre6 air thro"gh the solid "ntil it is dry. e e placed the solid prod"ct in a petri dish d ish and stored it on a dessicator. !ATA !ATA A&! A&! !ISCUSSIO&S !ISCUS SIO&S Po6dered co1alt chloride heahydrate, g ilter paper, g ilter paper 9 prod"ct, g
•
5.05;H /.E;; (.*D00
Prod"ct $%P 9 prod"ct) 8 %P)+, g J $(.*D00 8 /.E;;+ J /.;/H5
•
Theoretical Kield# Kield# 1 molCoCl 2 • 6 H 2 2 O
J 5.05;H g CoCl 'O %
238 gCoCl 2 • 6 H 2 O
complexcompound nd 2 mol complexcompou ) %
2 molCoC mol CoCll 2 • 6 H 2 O
)%
250 gcomplex
mol complex lex 1 molcomp
)
J 5.*0H g $Co%&'()*Cl+Cl •
Percent %B) Kield# 1.6174 g
Actual Yield
J
•
Theoretical Yield
/00 J
/00 % J 4.25 4.25 07 g 38.05
Overall eG"ation#
CoCl ;'O %s) 9 &'5Cl%s) 9 D&'( %aG) 9 'O
❑ →
$Co %&'()*Cl+ Cl %s) 9 'O %l)
O3S-R>ATIO&S • • •
'eat 6as generated after addition of concentrated con centrated 'Cl. !issolving &'5Cl 6ith conc. &'( prod"ced a cold %endotheric) reaction. After storing the prod"ct to the dessicator, the filter paper t"rned 1l"e.
!OCUM-&TATIO&S#
R->I- O R-LAT-! LIT-RATURThis This epe eperi rie ent nt serv serves es as an intr introd od"ct "ctio ion n to the the area area of synt synthet hetic ic chei cheist stry ry 8 specifically, inorganic synthesis. The 1onds in coordination copo"nds are t6o:electron 1onds %li7e covalent 1onds), 1"t 1oth electrons coe fro the ligand %a Le6is 1ase 6ith an "npaired
electron pair). The etal ion serves as a Le6is acid %an electron:deficient species 6hich can "se its epty or1ital for the 1ond).
CO&CLUSIO& e concl"de that 6e synthesi4ed a coordination copo"ndF $Co%&'()*Cl+Cl. e also learned the different techniG"es in synthesi4ing. The possi1le so"rces of error in this eperient 6ere# 6ere# the ina1ilit ina1ility y to cople copletel tely y trans transfer fer all of the reagent reagentss fro fro the 6eight 6eight 1oats 1oats in to containers. Soe of the synthesis precipitate ay also have 1een lost in decanting leaving roo for even ore error.
R--R-&C-S# Retrieved fro# /.) http#<<666.acalester. http#<<666.acalester.ed"<7"6ata
