(ptce ue se slre stCtV)
_?IJIV + *lJzI <-
IJI T, + 'IJIY
(- IJI + 13ep
-zlf,I + *€N
(aseq e se stce IJBN)
ruorJo uorluJJuecuoc oql es€eJcur selnlos
qtroa
.q
'(LZg'd ''pe
,uZ'stuatualg arylo ["r|sgruaq3',reqsueg pue poo,taueerg ees) _zlf,I + nlJzl
,ecus +
€
'e
s'9
:peuJoJ eJ€ suor leql slseSSns flr,rrlcnpuoc ur es€eJcur uV
n'9
tJuS + €c:g
.zltgz =-
:
z ;o
_sgug +
=-
tdus + scrg
_tg.rg:
CBV + ECrg
*zc;fl
*3V +
IJI
'rOJ ol el€uoqJ€crq eql Uenuoc ol q8noue
1'tol't tnoq€ sI gd eqt'_toSH roJ 0'z pu€ 'eg3z11 roJ v'g '*r[e(ozH)lv] rog g'g3o senl€A Tdqll,rv\,
JioJ
+
o;H z <- _toJH + .otH
:zOJ urJoJ o1eleuoqJecrq crseq oqt qlrl\ ]cueJ suor runruo;pfq eq1
*OtH + *r[(Ho)s(Ozg)ry]
=:
OzH +
SI.&\E-I
,ft
lrol-pe1suo: g'sr,u.e1
*r[e(OzH)lv] :crprce sl *€lV
_tHB
pe(lfzueq)
€cIJ
ruelsr(s lueAIOS'srznel
OZH
.J
HOOJ€HC
'o
sgld
'p
SI, AE'I
IJON
US
't
ruelsr{s }ue^Ios'st,lrt e1
cH
scqs
'q
sr./Ke.I
_HO
EOEX
'z
uortrugec
es€g
plcv
z'9
sr,Le-I
tcex
]d
.J
SI,4AE-I
_iolJ
zos
'a
urelsfs luollos'sr,A,le1
JON
EcIf,
'p
lue.alos'srlle1
slod
IJI
.J
rue1s.{s
uelsr{s luo^los'f;mo1-pelsuorg'sr,{le1
NC€H3
urelsfs luellos 'srme1
AUrSrr{f,HJ rrordflJf,v-uoNo( ft{v
clc
'OIf,H
€cg
flsyfl-flJv
g'9
'q
'e
t'9
:g
uf,rdvHc
6
Acid-Base and Donor-Acceptor Chemistry
60
Chapter
6.6
SnCla + 2Cl--> SnClo2- is the primary reaction. NH4CI in ICI forms NHa* and ICl2-,
and the chloride ions are then transferred to SnCla.
6.7
KF + IFs
6.8
a.
The ions are [BrF6]- and [BrFa]*: 2 Cs[BrF6] + lBrFal[SbzFrr]
+
3 BrFs + 2 CsSbFo
--+
rl
b.
fBrF6l-
:
O1,(may be
distorted)
[BrF+]-: Ct,
-\
,-i'
I
F
c.
6.9
lBrFa]* acts as an acid, accepting F- (Lewis and solvent system concepts).
2 HzSO+
allow conductance in the pure acids'
6.10
6.11
6.12
L.
The structure has the Br atoms in a staggered structure,
resulting in an So sYmmetry.
b.
It may be easier to visualize this by using tetrahedral
As. An sp3 orbital on each As points inward toward the
benzene ring. Ifthe hybrid lobes have opposite signs of
their wave functions, they fit the symmetry of the n orbitals of the benzene ring to form
bonding and antibonding molecular orbitals. The bonding interaction is shown'
The very high electronegativity of O in comparison with Al pulls the bonding pair very close
to O. This increases the repulsion between the bonding pairs and causes the large angle.
^.
b.
The methyl groups in
(CH3)3N-S03 donate electrons
to the nitrogen, making (CH3)3N
a stronger Lewis base and
strengthening and shortening the
N-S bond.
(cH3)3N-SO3 HrN-SO:
N-S
N-S-O
1.91.2pm
100.1'
195.7 Pm
97.6"
The greater concentration of electrons in the N-S bond of (CH:):N-SO3 increases
electron-ele ctron (bp-bp) repulsions, opening up the N-S-O bond in comparison
with H:N-SO:.
6.13
a.
b.
The polarity of the Xe-F bonds concentrates electrons on the fluorine atoms, which act as
the cinters of Lewis basicity. As shown in the reference, which provides the crystal
structure of lCd(XeFz)l(BFo)r, the Xe-F-Cd bond is strongly bent at the fluorine and the
structure around xenon is nearly linear, with an F-Xe-F bond angle of 179.1".
The BFa- ion is smaller than AsFe-, and the charge per fluorine is also greater in BFq
making BF+- the stronger Lewis base. In addition, the higher oxidation state of
cadmium(Il) in lCd(XeFr)XBFo)z enables stronger interaction with the fluorines in
BF+- than occurs between the silver(I) ion and AsFe- in [Ag(XeFz)]AsFo'
,
'eprruorq eullreproq oql qlr.
punoduoc Jelncelolu lsolu eqt suxoJ lunrtup€J 'spunoduroc
cIUoI eJolu ot{l surJoJ lsopJeq oq} se curz pue spunoduoc Jelncelolu eJour eql srruoJ sorJes
A
zcSH oq plnoqs
eql ur Ielelu lsouos eqi s€ fJncJeur
IeJeueS orou e uo 'zlJ8H pue
sprnbrl JBlncelolu lsotu eq] pue zCpf,"4Aer^
pue zJuZ eq plnoqs sprnbrl cruor lsol'u eql 'uorJelrJc
srql Sursn 'llncuJrp eJoru eq plnoqs pu€ eBuBr{J Jelncelotu relEer8 sarrnbeJ uorlEzrJod€A
'cruor .,t11soru sr prnbrl oqlJI '(es€qd;ode,r eql ur selncolotu ol pouonuoc Sureq eseqd
ptnbtl aqt uI solncelou) rersee eq plnoqs uorlezuoden';elnceloru sr prnbrl eqlJI 'seruerlxe
ozlrl esoql uoealoq Surqleruos ro'selncoyoru luel€Aoc'suor;eqge3:o dn epeur oq uec pueoo,ll
eql uee,Aaleq sr elels prnbrl eq1 'serpedord ]uel€Aoc eruos qlrl{ 'cruor eJe feq} 'e}e}s prlos eql
ut e:e ,{eql ueq1!\.selncelotu Jo s}srsuoc eseqd roden et4J 'enJode slles osoql Jo ,{ue uaq16
"$111ce;
lenbe ,(1:eeu eJolu qlr,ln, suorue eql IIe qlr^r ourquoc pue 's1e1eur eurlJepJoq oJoru oJe runrtupeJ
pue JUrZ ',(13uor1s eJoru uor apglns Uos oql qlr.Aa seurqtuoc puu'1e1eru Jegos qcnru e sr 3g
6I'9
BI'9
'ssecord uollcnpeJ aql JoJ sernleredurel req8rq qcnur e;rnbeJ uoJr se qcns
'ssecord
sleletu JepJeH
8ur11erus eqlgo ,ftenocsrp pue sleleur oq] ol uorlcnpeJ leiueprcc€ ol pal
e^eq plnoc sero Sutureluoc $lcorJo osn {urqi aruos i(se.rgdurec) se;n1eredue1,u,o1 flenrlelar
qtl1ll lno peIJI€J eq uec slelolu JoiJos eqlJo oruos Jo uorlcnpsu 'lno perJJec ,(1rsee a:ou ere
r70) +nJ
+ onJ
z
JOC +
7,
Jzo+3vt
IzO
+nJ
(,
e{rl suor}ceoJ os 'suor Ieletu preq
ra8uorls € seq
tl
onJ
V
V
o73Y
J+ONJ
V
T,
JzO+3HZ-
z
se f13uor1s se
nJ
,
O?HZ
ue8fxo qlra eurquoo lou op suor Ielou
UoS
Cg + t cCIV <- eCg + _ICIV uorlc€er eql qlra\ 'suor epuong aql JoJ uorlc€Jll€
'peppe sl sCg uer{A\ '{H ul e^lossrp uec lles ICIV ',eN eqJ ' ICIV <- C + ICIV
LI'g
gf
g
'zrg ul ueql g6tg3.z.rg
ur releer8 sr sl€lrqJo *o pue *r egl uoa,tgoq fS:eue ur ocueJeJJrp eql esneceq
(,{8reue req8tq) qlSuele^€a reuoqs ol UIqs plnoqs (*o
*u) pueq uru 00S eqJ
(-
ra3sue4-e8:€qc sruJoJ ztg
'lou€qletu se qJns sluo^los Jouop qlrzrr sexelduroc
'zIroJ L'Z'g uorlces ur peqrrcsep slceJJe eql ol Jelrturs sr srqJ
'E
sI'9
'elntelotu (lueq) ,{1ery1 e;oru eql ONH 8ur>1eru '51uo flsuep uorlcele srour fpq8rls
uorielncleC 'flrsuep uoJlcele eroru serJJ€c I€]lqro *r oqlJo puo qJrqa uo spuedep ,g
qltlr SurpuoB '1*r ,*r zL zL zo aJnlcru]s cruoJlcele eql seq puu zO qlr^\ cruoJlceloosr sr _ON ?I'9
s,4loqs
f-4srrueq3 .roldeccy-rouoq pu€
eseg-prcv
9
ralduq3
62
Chapter
6.20 L.
6
Acid-Base and Donor-Acceptor Chemistry
pyridine + BF3:
*:
-,{L'd6:J,1';.h}r.ur,, = -2t erccar/mor or -er.6 kr/mor, about r0% row
pyridine + B(CH3)3:
^': -i!t;;i::Ti'i,r:;r??;;l):
6.21
-r8 r kcar/m ot or -i5
ikJ/mor, 5 to 18% high
b.
Fluorine is electron-withdrawing, CH3 electron-releasing. Therefore, B in BF3 carries
greater positive charge and interacts more strongly with Lewis bases such as pyridine.
c.
The harder acid BF3 interacts more strongly with the borderline base pyridine.
a
NH3 + BF3:
AH:
:
-(ENn,Euo, + C*".C"0. )
-t(1.36X9.88) + (3.46)(1.62)l
: -19'0 kcal/mol
ot -'79'5 kJ/mol
NH, + B(CH:)::
lH :--(r*",8u1.n,,,
:
+ C^",C"1.n,y,
[(1.36X6.14) + (3.46X1.70)]
)
: -r4.2kcallmol or -59'4 kJ/mol
The order is pyridine +BF: >NH, + BF: > pyridine + B(CH3)3>NHr + B(CH3)3. The change
From BF: to B(CHr): is larger than the change from pyridine to NH:'
6.22
Absolutehardnessparameters:
IArt
15.81
BF:
10.7
NH:
9.3
csH:N
N(CH3)3 7.8
-3.5
-5.6
-0.6
-4.8
9.7
8.2
5.0
6-3
The difference between the HOMO of pyridine (9.3) and the LUMO of BF3 (-3.5) is smaller
than the other possible interaction, so this pair has the largest -AH, in spite of the difference
in hardness. By comparison with the nitrogen compounds, B(CH3)3 is expected to have an
absolute hardness lower than that of BF:, approximately 7'5-8'
6.23
form
CsI and LiF fit Basalo's principle that ions of similar size and equal (but opposite) charge
not
fit
they
do
and
different,
very
are
that
sizes
ionic
have
LiI
the least soluble salts. CiF and
combinations,
hard-hard
and
soft-soft
are
LiF
as well into an ionic lattice. In addition, CsI and
which combine better than the hard-soft LiI and soft-hard CsF'
sl
HO 9 + *€[e(OzH)cS]Z <- OzH g I + tozcs uortceor eqt 't1nse; e sV 'uol
eprxorp,{q qlra u€q} Jel€.,!\ qlr.ld Jeneq sourquoc Jr os 'regos pue re8rel IIIts sr *ccs 'uorlnlos
'elqrssod
ur serceds reqto eql uo Surpuedep '(eseq e se 8ur1ce) *r[e(OzH)lV] -ro (prce uu se 8ur1ce)
.regos pue re8rel sr uor
,e6z1y ul .(92.6:'X4
_[o(UO)tV] reqtro ruroJ u"o lI
*rlV e{l
tGO)gZ <- OzH € + EOzg '}1nse:
ctptce ,(11eam f.le,t sI uollnlos er{} pu€ ',sogzH + ,H
e sy 'f18uorls suor aprxo eql ol uo sploq *Eg pr€q'11eus eqi'e6zg uI ']r lue.\eJd s;olcug
roqlo sselun _HO Z <- OzH + _,O :eplxorpfq rurog-=01Jel€^\ qlrl\ slc€eJ uor eprxo 'yereue8 u1
8Z'9
'ilncuJlp e;oru eeyqg o1
Surpuoq sel€tu ocueJpurq crrols 'uorlrsod 7 eq1 ur lfqleru qlr.l" ';ene,,rroH 'N eql ol .{lrsuep
uortcolo sppe dno;8 1,(qlaru eq] 'ureay 'eurpr"r,(d1,{qtern-Z < eurpu,{d 4 eurpr"rfdl.{q}ehl-t 'p
'(EtZ 'dd) uorlellos
ol enp ,(lqeqord 'pelquercs sr JepJo eql 'uorlnlos u1 'ueSor}Iu eql o] ,{Isuep uoJlcale
etnqrrtuor sdnor8 1,(q1eur eql esneceq eseqd se8 eq] ur es€q 1se8uo;1s eq] sl N€(€HJ)
'c
'Jeqloue
slc€Jll€ 1nq 'sueSorpfq umo slr sploq .{yuo 1ou 1r ieql q8noue e3re1 sr ,{lrsuep e8;eqc
'qS ro d Jeqlre ueql e.trle8euoJlcele eJoru sr N osn€ceq eseq lse8uorls eq] sr EHN
'q
'crprcs pue errrlrsod oJoru sr ueSorp,(q aql 'aJoJoJeqJ
'qS Jo uS Jeqlre u€q] sl.rle8suorlcelo eJoru sr oJ osneceq 'plce lse8uorls eqtr sr zHeJ
'E
LZ'9
'uorlceJelur Uos-Uos e ur eSe8ue ./v\. pue uoqrec iruole 1y repreq oql qlr.tA spuoq pue elncelotu
slqlJo pue..repr€r{,, er{lsr OJJo ue3.{xo oqJ 'OI'€I e;n8rg ees) 16-36-lV sl repro orlJ
9Z'9
eqJ
'ozrs uo poseq 'opglns JoJ lsolleus 'epr:o1qc
oql roJ lse8rel sI suolue eqlJo uolleJpfq 'uotltpp€ uI '(_zS < _I < _Jg <_lJ rep;o)
suorue Jegos eql qlr^\ suorlce;e1ur re8uorls s€q
Sqd <.tqa
'rep"ro
-,gd
I
ouorl€c
zrgqd <
l3tos ,{ye1e:epotu e
sV
zlJqd :seIlIIIqnloS
'q
eql q}r,r,r Sureer8E'-,Efl JoJ lsolee,/K ',,3y41 rog lse8uo4s eq1 sr
suorlsc eqlJo uori€Jp,(g 'sle1sftc oql ur uorue e1e31ns e3re1 erjl qlr,Lr rsDaq lu suorl€c
re8.re1 aql 1nq 'sezrs uorl€c o] onp JopJo osJonor eql lcrpard socJoJ crl€tsoJ]oelg
'{lrlrqnlos
toseg < IOS.IS <tOSeJ < oos8ru
H
EHJ
'Uos eJu trrol€ H eql
ul3
pue'repreq
3.rt1ltu ue3,(xo
l, uoqrec eqt Surppy 'f,1"{lt eroru
sr
,--)
'HJ
I
o
H
H..-..O
tI
+
€HJ-C-JcH
<-
3-ltH
tl
tl
o
o
H
HO
'pJeq sr O'Uos sr
'{-4snueq3
3
',(1ery1un sr
roldeccy-.rouoq pu€
'v
H
I
puu
:serlrlrqnlos
"lr"
"HJ + J"
awg-prcv 9 relduq3
H
I
I
H...'.O
+
EHJ-JEH
vz'9
Chapter
6.29
^.
6
Acid-Base and Donor-Acceptor Chemistry
+ 2H2O -) Ca2- + 2H2I + 2 OH- Calcium has a lower electronegativity
than hydrogen, so CaHz is Ca2n1H )2 and the hydride ions react with the positive
CaH2
hydrogens of water.
6.30
b.
HBr + HzO -+ H3O* + Bi Bromine is more electronegativite than hydrogen,
so the hydrogen is strongly positive and is readily lost to the lone pair of water.
c.
H2S +
d.
CH+ + HzO
H3O* + HS- Sulfur is slightly more electronegative than hydrogen,
HzO :
and the positive hydrogen in HzS can dissociate to a small extent.
no reaction. The C-H bond is almost nonpolar; the hydrogens are not
positive enough to be attracted to the water lone pair.
-+
BF3 > B(CH3)3 > B(C2H5)3 > B(C6Hz(CH:):), Alkyl groups are electron-donating and increase
the electron density on B and reduce the attraction for the lone pair of NH:. The large
mesityl groups reduce the adduct formation because they are too bulky to fold back
readily into the required tetrahedral geometry.
6.31
6.32
^,
CH3NH2 is a stronger base. The methyl group pushes electron density onto the
nitrogen.
b.
Although 2-methylpyridine is the stronger base with smaller acid molecules, the
methyl group interferes with adduct formation with trimethylboron (F-strain) and
the pyridine-trimethylboron formation is stronger.
c.
Trimethylboron forms a stronger adduct with ammonia because the three phenyl
rings of triphenylboron cannot bend back readily to allow the boron to become
tetrahedral (B-strain).
a.
With the acids listed in order of increasing acidity:
H:AsO+
22
pK" (9-7n)
pK, (8-5n)
pK, (exp)
b.
H2SO3
H2S04
-5
-aa
1l-L
HMnOq
-12
-7
2.2
9.2
1.8
-11
With the acids listed in order of increasing acidity:
pK,
pK"
pK,
(9-7n)
(8-5n)
(exp)
Dimethylamine acts
HCIO2
2
3-2-1
2
HCIO
9
8
1.4
as weak base
HCIO3
-5
-1
HCIOI
-12
-10
in water, with a very small amount of OH- provided by
(CH3)2NH2* + OH . Acetic acid is a stronger acid than
the reaction (CH3)2NH + H2O :
water, so dimethylamine acts as a stronger base, and the reaction
(CH3)2NH + HOAc
-+
(CH3)2NHr* + OAc-
goes to completion. 2-Butanone is a neutral solvent; there is no significant acid-base reaction
with dimethylamine.
'sd'IcJo suorl€crlddB pue uorlruuep polr€lep
eroru B JoJ eoueJeJal eql ees '98'9 uelqord ur ,(geuq peqrJcsep
sr
led
sr/Ke'I pel€Jlsn{
V
LE'g
,XU
sCeJ:,U
6HtJr: u
\
f,T
/'x
,u-,.,'[--o/N1n-6t.,'q
,d'-U
'i(sCa3)g prc€ sr.&\o'I oql qll^{ puoq e Suruuo3 ue8,{xo e,trleSeuo:1colo ororrr oql qlr.^r
'uo:oq oql pue eurqdsoqd oqtJo ruote sruoqdsoqd eqt uee.,t toq e8prrq e su stce OzN oqJ
e Surnr8
.E
9E'9
'tgN-gEIC ur (puoq 1q-g re8uorls pue) uorlc€relur ]uol€Aoc ;e8uo"rts
rouop eq] qlrm r(18uo:ls oJoru lclpp€ ol elqu sr luql OW11
"HNJo lellqro
f8reue re,trol e ssq
tlJg
tlJg
eql ur puoq:e8uo:1s eql ur rolc€J ledrcuud
eq1'pe,r1oa.ur eru srolceJ ,(ueru q8noqllv ']cnppu iCg eql ur uuql lcnpp€ EIJS eql
ur f8:eue uorl€rcossrp puoq N-g raq8rq e .^\orls suoqelncl€o oseql 'tHN-gtX slcnpp€
eql uo suorlelncl€c orlrur q€ uo sesncoJ lnq Iepou dJ'i or{i Jeprsuos }ou seop elcru€ srqJ
]€q] sr lcnpp€
'q
'punoduoc srql JoJ fydde plnoc lueun8ru relrurs
'ergggo ,Qrcrseq srnoT olrleleJ oql ssorppe lou soop olcrpe eqJ 'tHN pr€,AAol
€lJg ueql es€q sr,ltol Je)ee,4d, e sl iCg ]eql sr lueuelnbe: fSroue srqlJo ecuenbesuoc
eq1 ('ecue.reJeJ eq] ur pelueserd ere luerunS;e srqlJo uoddns ur suor1e1nc1e3)
'€lJg uolsrp ,(pepuls o] ueql f1r:eueld ruo.r; rgg Uolslp o1 perrnber sr ,(8:oue eroru
'ruo1e eur:ong oqlJo ezrs IIerrJS eql pue C pue g uoe,laleq ecuaJeJJrp,(1r,nr1e8auo4cele
s3:u1 aql;o ecuenbesuoc e'puoq J-g oqlJo q13ue4s oqlJo esn"teg 'srncco ,&leruoe8
leuo8rrl ruo{ uoruolsrp eql se es€eJcur lsnu ecu€}srp ueSoleq-uoJoq eq} '1ue1suoc
,{11er1uesse ur€ruoJ secuelsrp pepuoquou eseqJ esn€oeg 'Jeq}o qcee q}ra\ }Je}uoc ur ureureJ
stuole aseql leql 3ur1se33ns '1ue1suoc ,{peeu eJe secuelsrp 13...lJ pue {...{ pepuoquou
eq] Iopour dl-I oql qllla' pJocc€ ut ':onoltoq ileprruerfd leuo8rrl ol reueld uorg
se8ueqc uoroq punore f:laruoe8 aQl 'e1151qlr.Aa lcerelul tlJg pu€ tCg sprc€ sr,l.ral eql sV
e 1nq
'seuell€ qlr. A ]ceer ueJ uoq] suor
osoqJ
eCqS
+H
CH + sJqS
:09 esuercep pue uorler1ueouoJ,H eq] eseerour
o] slJpoJ gH ul
s9
f-4srureq3 roldeccy-rouoq pue esEg-prcv 9
relduq3
sg'9
sgqs
nE9
j,
66
Chapter
6.38
a.
6 Acid-Base and Donor-Acceptor
Chemistry
t
below'
The energy diagram and the orbitals are shown
il
:i
@@ffi
The
b.
HoMo
The n*
;;t
density on
is the n*, with greater concentration of electron
N'
can combine with the
and NoH:
HoMo, concentrated primarily on the-nitrogen of No_,
# r, orfi ui, fo"ing HNo, a 6ent molecule' Comparing HNo
NOH
HNO
%
ffi@
HOMO
HOMO-1
ffi
#'
@"
predict that HNo is more stable than
Neither is highly stable, but calculations
NoH'
N
H
gc
,:l
\
\
\!/
N-g
g'H
{
'uoJoq eql pJe.4Ao] pozrJelod sr 'sruol€ ueSoJllu pue uoJoq
oql ueo,lueq epou € s€q qcrq^\ 'l?lrqro Surpuoqrlue Suqcleu eq] iueSorlru e,rtle8euo4cela
oJotu eq] pr€, ao] pazuelod st 'noyeq u,t.roqs 'lellqJo J€lncelotu Sutpuoq N-g eqJ
',{lenrlcedseJ
'l
€'g pue €€'S se;n8tg ees 'EHN pue egg;o slellqJo
JoC
'q
'v
0v'9
pue .€I I sl rg-O-g) ey8ue leuo8ul e
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